This is old news, but it was only today I followed a link to page by a guy named Leo Bodnar. Among other things he has posted an eMac Upgrade Guide. My favorite bit was the amazing photo of the resistors the author removed to uncripple his eMac's processor and ramp the speed up from 800MHz to 1.33GHz! After a bit of googling I also found a SpyMac discussion and a MacNN discussion about the upgrades.
It's the man himself! I feel honoured
Thanks for pointing out the MacRumours discussion - much more in-depth than the SpyMac and MacNN ones!
Hi there! There is also a long discussion on MacRumors
http://forums.macrumors.com/showthread.php?t=53733
Best wishes
Leo