Great gift. You'll love it.
Actually, you can have any computer set up to "share" with 5 others and they can do the same. If you are on your friends "buddy list" you can get songs from them. I also believe that you can choose how you want your Ipod to work with the computer. You can set it up to automatically "update" the Ipod or you can choose to do it manually. If you choose the manual route, when you plug the Ipod into the computer, you can choose what songs you want to load onto the Ipod. One other tip, if you plan on listening to your Ipod through anything other than the supplied earbuds, you may want to upload music to ITunes at a higher bitrate than the standard rate of I think is 96bit. Change it to 128 or higher and the quality difference is huge. You wont be able to have as many songs on the Ipod but the quality, if played over a home stereo or through quality earbuds or headsets is noticable.
You do need ITunes to load songs onto the Ipod and you need a computer to do so unless you have the IPod Touch which allows you to download songs via any WiFi network.
I see you have a couple of choices. If you don't have access to a computer, but do have access to a buddies computer who already has ITunes, have them make a folder for just your song library. If you go to the Apple Website and type in "how do I use 2 Ipods on one computer", they will give you three options on how to do so. You will need to use your buddies computer to upload any songs you want on the Ipod but you could at least have your own folder.
Other option would be to trade in the Ipod you got and go with the Touch. It will cost more and then you can only purchase music from ITunes or other sites where you can get music via the internet. I got my son an IPod Touch 8GB for Christmas and found them on sale through Best Buy for $179 - or $30 more than a new Nano. The WiFi access alone was worth the $30. Look for stores that offer a in store gift card if you purchase an IPod. I know that Target is now offering either a $20 or $25 gift card with a Touch purchase.
I just got a cool addition to my Ipod. My wifey gave me the Apple Airport Express which allows me to carry my IPod Touch around with me and stream my music from my Ipod to my home stereo. So, I can now literally carry my entire music library around the house with me and choose from the IPod the song I want to hear. It then goes from the Ipod to my computer and then wirelessly to the Airport Express which then plays through my stereo. When I built the house, I wired the whole thing for music and video distribution and IR access from anywhere to any piece of equipment. It took some figuring on how to make this all work but I love this kind of stuff.
Mark W