ahh, you beat me to it Darkside_tanro, but I'm glad you did start this thread ;)
Since we're in The Workbench, and a 'common' answer to questions is "get a new XXXX, get more XXXX" this thread seems fitting....
Here's a few more sites to add:
MySimon (
http://www.mysimon.com)
E-bay (
http://www.ebay.com) (seriously, you'd be surprised)
MemoryOnly (
http://www.memoryonly.com)
Compu-Terra (
http://www.compu-terra.com)
PC Surplus (
http://www.pcsurplusonline.com)
*would make for a nice Sticky ... IMHO
(hint,hint,wink,wink,nudge,nudge) *