Deal starts at 3pm PDT on 5/26/11. This adapter works in Windows, Mac, and Linux.
This is an incredibly small adapter and the range is pretty good (as good as the built in wireless on my laptop). The chipset is a Realtek 8188CUS.
I have personally used it in Linux, both 32-bit and 64-bit. It does require the compilation of a kernel driver and the latest drivers are here (http://www.realtek.com.tw/downloads/downloadsView.aspx?Langid=1&PNid=48&PFid=48&Level=5&Conn=4&DownTypeID=3&GetDown=false&Downloads=true#RTL8188CUS). Either kernel 2.6.39 or 2.6.40 will include native support for this adapter, according to the kernel dev list. It does not need a separate firmware.