Miniature WiFi USB Module for Raspberry Pi
Make your device cable-free by adding WiFi. Take advantage of the Raspberry Pi and Beagle Bone's USB port to add a low cost, but high-reliability wireless link. We tried half a dozen modules to find one that works well with the Pi and Bone without the need of recompiling any kernels
The latest Wheezy distributions support this module out-of-the-box. You may find that you need to have a powered hub to use this adapter, so if you're having power flakiness with your Pi, try a hub.
Please note: The WiFi module may look slightly different than above, but all modules shipped are Pi-tested and contain the same chipset and have equivalent performance, the only difference is the plastic shell.