I come from Germany so my english isn't very good ;-)
I'm using Ubuntu since the 8.10 realese, now I need Windows just for iTunes to add apps for my iPod touch 3G.
I've got a middle-class PC from 2006. It's from the disocunter "Aldi" (btw AARGH!) with a Pentium D 2.8gHz (maybe dualcore), 1GB RAM and a stupid grafhics card (s3 UniChrome VIA).