Originally posted by SirCastor:
Can one use Non-Airport cards in the airport card slot in the G4 sawtooth?
No.
All other vendor's card include attached antennas, which are designed to stick out from a laptop's PCCard slot.
Apple's AirPort cards, on the other hand, do not include an antenna, instead they have a socket into which you connect the antenna built into the G4's case. This means that you get a better signal, but other cards won't fit.