First, I'm not an expert, you'll have to talk to someone else if you have difficulty. Second: this is only a list of what has worked for ME. Your mileage may vary; but it is a comprehensive list of getting at least SOME media and APPs on your phone. You will probably want to skip down the list to installing PC Studio, since the first section is really specific of what worked for me.

Also, I discovered nothing in this guide, it's just a rundown of things others have written here, mostly by
Agoattamer, who appears to have discovered and compiled 99% of the useful info here. Speaking of which, admins should feel free to edit this post for errors and as more info comes in.
One thing I should mention here: Do NOT connect your phone until in Section 4. I'll write when to do it.
Section 1: Start with a Clean SystemYou probably won't want or need to do this but it's what I ended up doing.
Step 1: Install a clean Windows XP Professional 32-bit on a 32-bit computer.I seemed to have issues on a Gateway that I was using when I tried to install PC Studio on the Gateway custom Windows XP Media center. Also known as 'crap that Gateway sticks on your computer for extra money.' I wiped it out and installed a totally fresh OS.
Step 2: Install driversGonna need some drivers. If you don't know what drivers are, you may want to stop here and rethink messing around with something that will brick your phone. Or at least go look them up somewhere else and learn something new.
Step 3: Install Windows XP Service Packs 1, 2 and 3 The best way to do this is to download something called the Windows XP SP1 Redistributable, and 2 and 3.
Step 4:Reboot your computerIf you don't know what that means, hit yourself with a brick.
Section 2: Install PC Studio and get TKFileExplorer 2.2 and JADgenStep 1: Download TKFileExplorer 2.2Download it from:
http://rapidshare.com/files/182411456/TkFileExplorer.zip Click free user, wait your 25 seconds, download the zip. Extract TkFileExplorer_2.2.exe and TkFileExplorer.ini out of the zip file to wherever you want to keep them. This program runs stand alone and doesn't need installed. We'll get back to it later.
Step 2: Download JADgenI got it from
http://www.filestube.com/c1f288c4065a402003e9,g/JADgen.html Knock yourself out. It's also stand alone and we will return to it later.
Step 3: Get the Version 1.4.0 (Build IL2_4) version of PC StudioThe NPS.IB5 version is supposed to work as well. This version is not actually the official Impression version, but a version used for the Solstice and Eternity models.
Get it from
http://www.samsung.com/us/consumer/mobile/mobile-phones/at-t-phones/SGH-A887ZKAATT/index.idx?pagetype=prd_detail&tab=support# You will need to click 'software' to see it, which is kind of dumb but whatever. Search for 'Software' you'll figure it out. You will not need the USB drivers, as they come with PC Studio, so only get the top one by clicking the little exe icon, agreeing to the terms of service and clicking the exe icon again.
Step 3: Install PC StudioDouble click New_PC_Studio_1.4.0_IL2_4 and install it. DON'T RUN IT.
Step 4: Reboot your computerOk, you probably don't have to do this but what the hell, it won't hurt anything, except for adding another tiny puncture wound in Mother Earth's total energy supply.

Cue Sara Noxx/Project Pitchfork-Earth Song:
http://www.youtube.com/v/j5v5p4RAh-s&rel=1 then get motivated to burn your refrigerator's cooling unit because the song is so awful.
Step 5: Set up PC StudioLets change some setting in PC Studio, so start PC Studio up, click the Settings at the right side of the bottom row of icons. Uncheck the boxes that say "Start PC Studio Monitoring with Windows" and "Start PC Studio when device is connected"
Step 6: Stop PC Studio's connection monitoringIt will be in your taskbar's tray looking like a little light blue puzzle square. Right click it and turn it off.
Step 7: What the hell, reboot your PC again.PC studio installs some USB drivers, so you'll want to reboot here, as USB drivers are notoriously finicky.
Especially the ones for cell phones. If you wanted it to be easy, you should have gotten an Android phone. Feel free to get suck(ered) by the iPhone hype too, but as far as my experience with Apple iTunes connectivity is it will drive you batsh*t. Screw Apple.
Section 3: GET PSYCHED!Ok, you're just about to plug your phone in, but I strongly recommend being at least a little prepared. This means either having all of the files you want to copy to your phone
already downloaded and good to go; or have a nice fat block of time to find them.
Why do I say this? Because I have no idea when your install will crap out on you. You might only get one shot at it, and believe me, trying to uninstall and reinstall PC Studio and it's USB drivers is a pain, and you might have to resort to Section 1 without serious registry/device manager know how. Not a good option if you're using your main PC.
I don't necessarily want to freak you out, but at least have a couple of good wallpapers and all the apps you don't really want to live without ready to go. That way you won't regret not being able to get back on again so much. At least get a few non-generic wallpapers, MobileNotepad, a scientific calculator, a File Explorer, 365 Solitaire and Tetris. You can never go wrong with Solitaire and Tetris.
Section 4: Connecting the Samsung Impression to PC StudioStep 1: Open PC StudioDo this before plugging your phone in.
Step 2: What the hell (version 2), Reboot your phone.You heard me.
Step 3: Moment of Truth, plug the phone in.The search icon in the upper right of PC Studio should pulse some curves around it for a little, and your phone should appear underneath it in a few seconds. In the taskbar you will see the New Hardware connection bubbles appear, ending with, "Samsung Mobile Modem" found.
If your phone does not appear beneath the Search icon after a minute or three, you can try to click the 'Search' icon and connect to it manually. If you get an error like "The connection is being used by another program" you're SOL and I don't know what to do for you other than returning to Section 1. Feel free to search the forums and ask people. Hopefully an admin will edit this section if they know or learn more.
Step 4: Upload Wallpapers, Photos, Ringtones, and Songs.Now is the time to upload all of these that you want. Be sure not to go too heavy on the songs unless you only have a couple of apps to add. PC Studio is pretty simple to use once your phone is detected, if you can't figure it out pretty easily, go to the Samsung site for tutorials ect.
http://www.samsung-impression.org/ring-tones-and-free-wall-papers/Please contribute wallpapers! They're real easy, just use Paint.net from
http://www.getpaint.net/ to resize the image and make the canvas size 240px by 400px. Nothing impresses the ladies more than an obviously customized wallpaper. (And before you ask, no, you cannot change the lock screen's background. Yes, we know it's retarded but it's locked in somewhere.)
Step 5: Without disconnecting your phone close PC StudioSection 5: Uploading AppsStep 1: Open TKFileExplorer_2.2Simple enough.
Step 2: Set up the ConnectionIn TKFileExplorer go to 'Setting' and click COM. Click the drop down menu called Port and there should be one COM with a number, such as COM4, COM5. Select it. Don't change anything else and click OK.
Step 3: Click ConnectYou can use the File Menu > Connect if you cant figure out which giant button is the connect button at the top. Dumbass.
Step 4: Review File System and a warning[/b]
Ok, in the bottom two panes, you should have a Phone 'disk' icon and a nice list of folders and files, starting with list. There's a lot you can do here, INCLUDING PERMANENTLY SHAFTING YOUR PHONE'S OPERATING SYSTEM. If you don't know what it is, or what it does, DON'T F*** WITH IT.
Moving on; because we have gonads of cold iron.
Section 6: Installing an appStep 1: Getting and prepping the app.Lets grab a copy of Noteable, a simple word processor from
http://www.samsung-impression.org/third-party-samsung-impression-software/noteable-beta-java-app-by-bantam-bytes-mobile/ If you can't download it from the bottom of the first post, it's because you haven't registered and signed in to samsung-impression.org so make yourself an official n00b already, instead of an unofficial b00b.
Stick the noteable.jar in a folder on your desktop named 'Apps'. Feel free to put your other .jars in there. Or use a different place. Whatever.
Step 2: Create the .jad fileRemember when we got JADgen? Grab JADgen and put it in your Apps folder. Drag noteable.jar on top of JADgen like you were dropping it into a folder. JADgen will automatically create noteable.jad in the same folder. Masochists can open JADgen and type the whole pathname to the .jar if they're feeling especially kinky.
Step 3: Navigate to the Application source folder in TkFileExplorerYou cannot drag and drop directly from the desktop with TkFileEplorer, so Navigate to the Apps folder in the top left pane of TkFileExplorer. Probably C:\Documents and Settings\<your login name>\Desktop\Apps or something. You should see noteable.jar and noteable.jad and probably JADgen.
Tips and Tricks with TkFileExplorer (TKFE)Now's a good time to mention a few things.
1. TkFileExplorer does not update folders like most file explorers. That means that if you change something in a folder, such as moving a new .jar into your Apps folder, you will have to click on a different folder and then click on the Apps folder again.
2. The Phone section of TkExplorer can be twitchy and weird due to the above. When you create a folder you'll want to go up a directory and re open the directory you made the folder in before you can access your new folder. You might even need to click the - next to Phone and reopen every folder again.
3. While copying something over tkfe frequently disconnects. While moving between folders(directories) tkfe disconnects. Moving folders is actually copying a tiny text file listing the folders in each directory, a random fun fact for all you home gamers. In a UNIX operating system you can even edit a folder with a word processor. You might even add a '\a' to one of the names, at which point your file name will be something (pc speaker beep). Your buddy might even go a little nuts trying to open it.
3 cont. Anyway, don't panic, just Reconnect. You may need to reboot your phone or pc but hopefully you can just reconnect again. Try to avoid doing anything that might cause your PC/phone link to change, but if it ain't workin, do what you can.
4. Sometimes TKFE will seem to hang but actually be working. Let it sit for a little bit. Don't copy one file immediately after the last one finished. If it has a problem it will pop up an error message, so let it sit if there's no error message, even if it seems like it's not copying.
5. Sometimes it will disconnect halfway thru a file copy. Don't panic, just reconnect and copy the file again. It may take a couple trys but it should get there eventually. You can confirm by matching the file sizes in the top and bottom panes.
6. It's usually better to delete new apps with the phone if you can. Just disconnect from TKFE, (Not the USB cord.) and use your phone. This is also how you can check your phone's memory capacity - just use the phone while it's connected. EZ-PZ.
Step 4: Navigate to the Impression's downloaded Games folderThis is on the phone, the lower two panes of TKFE at
Phone/Exe/Java/Games/Step 5: Create a folder named for your appIn this case, we'll make one called Noteable. The name of the folder will be the name that appears in the Apps menu.
Step 6: Go to a different directory, such as ExeThis is to refresh the Games directory so we can get in the newly created Noteables folder.
Step 7: Go to the newly created app folderAgain this will be /Exe/Java/Games/Noteable
Step 8: Copy the .jad fileMove noteable.jad from the upper right pane in TKFE to the lower right pane. It should copy over very quickly without an issue.
Step 9: Copy the .jar fileMove noteable.jar from the upper right pane in TKFE to the lower right pane. This is what usually causes TKFE to disconnect. Reconnect and try it again until it takes. You will quickly create superstitions about this, such as moving the mouse slowly to the right and up makes it work better. Or using the Upload button on the upper bar. Or sacrificing a cat. Y'know, whatever works for you.
Step 10: Go back to step 1 and repeat the process for all the apps you want on.You will need a new, separate folder for every application.
Step 11: Delete any locked apps you don't want.I may go to hell for mentioning this, because I strongly recommend just leaving them on if you're not sure about what you're doing. They're not very big. Anyway, now's the time to do it. All you need to do is go to Phone/Exe/Java/Locked Games/ and delete the folders that matches the app you want to get rid of. You want to get rid of MusicID, delete the folder called MusicID. At the least you should probably avoid deleting your AT&T Navigator, Media Mall, Mobile Email, Where, and Yellowpages.
Step 12: Use the MASTER KEY!!!Special thanks to Agoattamer for discovering the MASTER KEY. And pretty much everything else. To make our new apps viewable, we've got to rebuild the java database on our phone. People used to have to pretty much wipe the phone's settings files and force it to rebuild everything to do this but thanks to the MASTER KEY, we can access the debug menu and do it. So without further ado:
Oops, I forgot some ado... DON'T F*** AROUND WITH THE MENUS! Again, you can give your phone cement shoes by hitting the wrong thing. If you have fat fingers you might want to use the keypad and numbers. Tubby.
1. Disconnect from TKFE, you don't need to unplug the phone.
2. Open the Dial Menu on your phone.
3. Dial *#6984125*# The second you hit the # button a menu should open.
4. Select 4. Internals
5. Touch the input bar for the MASTER KEY!!!!
6. Dial the correct MASTER KEY!!!! for your language and hit OK then Confirm.
*#3818790*# is for English
*#3818792*# is for French
*#3818797*# is for Spanish
7. Select 6. Storage Settings
8. Select 3. Update Java DB. Wait for it to finish.
9. Select 9. Update app database. You'll have to scroll down.
10. Press your Multitask button, select Games and Apps. You should see your new app!
11. If your new app has a puzzle icon instead of it's own icon and does not load, reconnect to TKFE and re upload it, if you got it from a confirmed Impression site, it was probably just a bad upload.
12. Press the back button on the center bottom of your phone to get back to the Storage Settings menu. Again, Masochists can type in the MASTER KEY!!!! every time they test an app but they're into that kind of thing.
Step 13: Add LOTS of appsAn empty phone has about 200,000K of space. I haven't seen an app over 1024k yet, so you've got space for over 200 apps. On the flip side, an mp3 is from 3,000 to 7,000k. Do the math yourself, I'm tired.
http://www.samsung-impression.org/games/full-screen-touch-games-and-apps!!!!/http://www.samsung-impression.org/games/http://www.samsung-impression.org/third-party-samsung-impression-software/Step 12: Click Disconnect in the TKFE bar, double click Safely Remove Hardware in the Toolbar task pane and stop the USB Mass Storage DeviceMight as well be professional. You might have more than one USB Mass Storage Device if you have a USB hard drive or flash memory stick or camera or gadget of some kind. Feel free to stop them all and unplug and replug the other devices.
Step 13: Unplug the PhoneNot very mobile of a phone if you don't unplug it. It should be bloody charged by now.
Section 7: Let Agoattamer pop your collar.You just pimped your phone.