Add another victim to your list.
S/N: G8429BC6QQJ
eMac G4 1.25 GHz
SuperDrive, 256 MB RAM
And the evidence:
http://www.engr.colostate.edu/~reinholz/unhappy_emac.jpg
Bought this eMac directly from the Apple Store in the USA in July 2004. Worked beautifully until the same symptoms ruining everyone else's day started happening about 2 weeks ago.
Rebooting in Safe Mode and moving every extension with the name "ATIRadeon" in its name out of /System/Library/Extensions seems to have helped, but the system still freezes, albeit less frequently. (No jibber anymore, though).
I plan to contact Apple Support (naturally I didn't buy Apple Care) and will report on what they tell me.
I had a PowerMac 7600 for years and years and never had a problem with it. That thing was rock solid--a little sluggish under System 8, but beautiful running 7.