wired news ran a piece the other day about UNIX drivers that have been ported to OS X (well, it's UNIX, too, but slightly different), which now allow many PCMCIA cards to work under OS X. the functionality is simple, and the second link is for a program that lets you send connect and disconnect commands to the base station.
This is powerbook-specific, as only they have the cardbus slots, but I've seen posts here in the past about folks wondering if their PCMCIA cards would work in their powerbook, so it also seemed a networking one. tooki, toss this wherever you deem more suitable.
http://wirelessdriver.sourceforge.ne...html#supported
http://edge.mcs.drexel.edu/GICL/people/sevy/airport/