SMC's USB 2.0 802.11g Adapter
SMC uses chips from Broadcom in most of its devices. Broadcom powers AirPort Extreme, too. So this USB 2.0 802.11g adapter would seemingly allow a newer Mac to use its USB 2.0 port to power a 54 Mbps AirPort Extreme (802.11g) connection without using an internal card. Anyone willing to try and see if the AirPort 3.3 drivers support it over USB?