If you haven't yet bought the Linksys card, then I recommend an Agere/Orinoco card (now owned by Proxim). There are indeed drivers for Mac. For an OS X driver go here:http://www.versiontracker.com/moreinfo.fcgi?id=11826
I have installed these cards in many Mac and PC notebooks, and all is well in WiFi.
HTH
Airport Extreme�Great For Windows Users
Airport Extreme�Great For Windows Users