I tried to search the forums to make sure this wasn't posted but it didn't work. Anyway here's one way to turn off AA in CoreGraphics (Cocoa and some Carbon apps):
1) type "defaults write CoreGraphics CGFontDisableAntialiasing YES" into terminal
2) logout and in
Type "defaults write CoreGraphics CGFontDisableAntialiasing NO" and log out and in to turn it back on.
To turn off AA in some Carbon ports, try TinkerTool.