Today’s Woot! deal is useful if you have an old computer using 802.11g and you want to bump your network to pure 802.11n and dump 11g compatibility for the increased performance. The Cisco Valet 300Mbps 802.11n USB Network Adapter supports 802.11b/g/n, and speeds up to 300Mbps on 11n, with WEP, WPA, & WPA2 encryption. And it is only $6.99 + $5 S&H.
Somewhat unbelievably, it looks like MSRP when this launched was $135.98, and Amazon is selling them for $24.99.