So, if you somehow lost your computer data and need to get some music back and the music is on your iPod, I know a way to transfer it.
Step 0: This method takes a lot of time. Seriously, unless you have a ton of time to kill, if there is any way possible to transfer it from another computer, a CD, a mini hard drive, or even if you put it in the recycle bin, then do it. I mean it, this can take hours depending on how much music is on your iPod.
Step 1: Show hidden files.
Mac:I am not sure, but I think on a Mac it already shows hidden files anyways. I don't usually use Macs, but I've looked at the school ones a bit, and didn't like them. As far as I could tell, it showed hidden files automatically, but I don't know.
Windows:I don't know about Vista or 7, but at least for XP and possibly other versions (I'm fairly certain this works with older versions too, but in my opinion if you use an older version you're crazy) go to Tools>Options. Then look through the tabs until you find one with a long list of options and checkboxes. Change "Do not show hidden files and folders" to the opposite. Then click Apply, and just to be safe click on Apply to All Folders, which should be above the list of options.
Step 2:Go to My Computer on Windows, or click on your iPod on the desktop on a Mac. OK, my iPod is a Nano, second generation, but this step should be about the same. If these exact folders don't work, just look through folders until you find it. But here is what works with mine:
[insert iPod name here] (E:)>iPod Control>Music
Inside there should be at least several folders with names like F05, at least for my iPod. Go through them and copy the mp3's into a folder on your computer or a backup hard drive. The mp3's should have names that are four random letters in all-caps. Don't bother copying the locked ones if you already re-downloaded your iTunes store music, because this is just your iPod's copy of it, and you have to use your password to open it anyways.
Step 3: I suggest using Winamp for this step. Go through your copied files one by one and open them preferably in Winamp. Then rename the file the correct name. Trust me, even if you have to do it again in iTunes, this is important. Here are some shortcuts that will help you when renaming the actual file.
F2 (or possibly Fn-F2) - I really doubt this works with a Mac, but on a Windows it is a quick way to rename.
Arrows and Enter - skip through the songs, and play one in Winamp or iTunes (seriously, Winamp works better for the renaming. It's very useful anyways, and it's free. Download it.)
Delete/Backspace - if you find a song you don't want anymore or already have elsewhere on your computer, delete it. MP3's take up a lot of room and actually it's best to copy the songs onto a small hard drive instead of your computer, especially if you have a large music collection. My music collection is like 3 gigabytes, but I know for a fact most people have more music than that. Actually I do have a lot of music, but most of the songs are fairly short (one is almost 40 minutes though) and also I delete the ones I don't listen to, so I end up not using as much space for my music.
I hope this helps. I'd avoid doing this though, it takes a lot of time. I may only have about 3 gigabytes of music, but that's about 400 songs that I had to go through. But if your house burned down and your computer and CDs were destroyed, this is a good option. OK, I'll admit I could've gotten the music from my old computer, but I had a lot of spare time to use up, and anyways I did this in my spare time during a road trip, so I couldn't exactly go home and get them off that computer and onto my laptop. I think there is a program for this that you could get, but it's not free. I don't remember what it's called.
Remember, it's all fun and games until the Ramblin' Evil Mushrooms attack.