Or you can buy a third party USB dongle; they're not badly priced and work pretty well (I have one on a 400mHz Imac that works fine). Most of the problems that used to exist with these on Macs was related to the driver, which as of November was fixed. HOWEVER, make sure that the dongle you buy has a Mac driver, many do not. I know the D-Link DWL-122 does.