Forum Moderators: open
I'll start.
G = Google
ATW = AllTheWeb
F = Fast
OV = Overture
Y! = Yahoo
T! = Teoma
AJ = Ask Jeeves
Es = Espotting
FW = Findwhat
ROI = Return on Investment
and here's some more courtesy of Brett's list over at SearchEngineWorld > SEO Jargon [webmasterworld.com]
Any suggestions or comments?