Comprehensive thread here on how to get your ipod working with Ubuntu.
I recently purchased an iPod Nano, and i can confirm that the Feisty Fawn live CD does indeed recognise it - it pops up on the desktop when you plug it in. However, i'm having problems with it being seen by my Dapper Drake laptop. "dmesg" shows that its being recognised at a low level, but Amarok and gtkPod can't see it. I'll probably just upgrade to Feisty anyway.