Here is how I was told how to do it - I have personally not tried it.
You can use the iPod Mini to share music between multiple computers, but it's not easy, as the player syncs to only one version of iTunes. But there's an alternative. We were able to copy MP3 files from the Mini to a second computer's hard drive in Windows by turning on "View hidden files and folders" and browsing the Mini's internal directories in My Computer until we found the music. Mac OS X users can do the same thing if they install TinkerTool.
[http://www.bresink.de/osx/TinkerTool.html].
The iPod Mini has no compatibility problems transporting data files between computers (Macs or PCs) when you activate the Enable Disk Use function. In this approach, the Mini mounts as a data drive, but it hides music files unless you use the above-described workaround.
zealot...i actually recommend that as an option. if you set your ipod options to "manually select songs" when you plug it into a computer you can select from pretty much anyone's itunes. i've done it (sadly, i am poor) but doing this once means that you can never autosync again unless you want to lose the songs from other people's computers. not such a big deal imho, but to each their own.
if u have a mac, u can get your friend's songs from his itunes. just copy his songs into one single folder onto his desktop. connect using firewire with his computer/laptop, and then have him move his mp3s over to you.
next, drag all of those mp3s into your itunes. proceed to syn with your ipod.
Here's the deal. If you have an apple, set the Ipod up with the PC first, then you have no compatability problems. Then you can do what you want.
Yes Itunes can have mult. ipods.
Yes one ipod can sync with multiple itunes.