Designed like the glass-holding suction cups thieves use in the movies, Buffalo's AirStation WLI-U2-SG54HP works to boost your wireless connection up to 210%. It works with Vista, has 802.11b/g, WEP, WPA-PSK, and IPv6 compatibility.
To get that amount of boost, unfortunately, the antenna has to be gigantic and ugly. That's actually an IETF RFC standard—RFC 4797 - Specifying Aesthetic Design For Wireless Component Enhancers. Look it up if you don't believe me.