you can install a last.fm plugin on multiple systems and use the same account. IIRC, Veronica was talking about not being able to use it with her iPod because it is Mac-formatted so her work pc wouldn't recognize it so she couldn't send her song info to last.fm (which can easily be fixed by formatted the iPod as "Windows", FAT32, which works fine on Mac's and Windows)
btw, iScrobbler is a great iTunes/iPod last.fm plug-in for OS X. There is one called something like "jscrob" for Windows that was pretty nice when I used it. There are ofcourse plugins for most other media players and some other portables.
V said on the show that she thought there was a plug-in for last.fm that got the info from the songs you listened to on your portable device. She then said she doesn't use it because she can't plug her ipod in at work. I am guessing this means she has last.fm installed at work. My question being: can you install last.fm on more than one computer? I listen to most music on my desktop except that I sync my iPod with my laptop. It would be a nice plug-in to have.