as long as they have the same OS (Windows to windows), or even windows to OSX, its pretty easy.
Go onto google and look for iPod Agent, IPod Util, etc, you'll find what you need. ipodlounge.com has a bunch of them listed in the freeware section. even ephpod will do it if you want.
Otherwise, hook it up, go and browse the iPod as a HDD, enable hidden folder viewing, and go into the hidden iPod_Control folder, then Music, and simply copy all of the 40 or so F1-40 folders to the new comp, then have iTunes open and organize them all.
Windows --> OS9 doesn't work tohugh, but thats about it.