Hey there
Rescued an iMac G5 iSight (Model A1144) from a bin a few weeks back. It works fine (barring the ubiquitous stripy screen).
After failing to get Ubuntu working I installed Debian, which works perfectly, although in Gnome I'm getting a few graphical anomalies, pictured here:
http://i.imgur.com/fPeup.png
I read that I needed to install the linux-firmware-nonfree package to get the Radeon driver working properly, but doing so caused the computer to crash on boot. No Xorg log, can't ctrl-alt-F1 etc.
Any idea what's going on?