Premiertek_com via eBay offers the PowerLink 150Mb/s 802.11n Wireless USB 2.0 Adapter
, model no. PL-14N, for $17.85
with free shipping
. That's the lowest total price we could find by $4 and the best deal we've seen. It features a max speed of 150Mb/s, dual 7dBi dipole antennae, operating distance of up to one mile, purported 6x signal strength, and support for WEP, WPA2, WPA-PSK, and WPA2-PSK encryption.