Oh wow, I definitely just found the picture myself while waiting for someone to respond! This is funny and sad because I have been trying to figure this out for months now. Anyway, I'll put the answer for those who wondering the same thing. The file is in the Finder. You open Finder, click on your name, open the folder marked "Library", then open images, and any recent iChat or Address Book pictures should be in there if you just click on "iChat Recent Pictures". Hope I helped anyone who was wondering the same thing as I was. Or maybe everyone already knew this?