D-Link DWL-G122 - Compact Wireless USB Adapter, 802.11g, 54Mbps $21.99

D-Link, the industry pioneer in wireless networking, introduces the DWL-G122 Wireless USB Adapter, part of the AirPlus G family of 802.11g wireless networking devices. Using the DWL-G122 Wireless USB Adapter, you can now enable 802.11g wireless connectivity for your PC using the convenience and speed of a USB 2.0 interface

Buy.com is carrying this Wireless USB Adapter for $21.99