Hehe, cheers Doc. Joshua though rude is correct, i clearly read stumbler for sniffer.
If you had read the kismac docs back in 06 you'd know that at the time airport express used some technology with some security implications, so a bunch of the working details about the airport express chipset where not available to the kismac developers to let them make a passive mode sniffer function with airport express cards.
You'll be pleased to know that it does work these days - though as fryke pointed out, most uses of it are dubious anyway.