I have noticed on an old 333 MHz iMac logic board that there are traces for what appear to be:

J12 = Mac floppy drive

J11 = CD analog audio

J4 = Serial port (Used for IrDA in original bondi iMac?)

J2 = ADB port

J6 = Marked "IrDA"

DS2,3,4 = Ethernet connection/activity LEDs

S2 = mystery button/switch

MEZZANINE = some crazy slot on the bottom of the board

Does anybody know about these or if they'll work if a connector is soldered on? I think I'm most interested in the floppy and ADB ports.