ihacked has created a long range smart wifi snooper for piggybacking off distant free or unsecured wireless routers.
It uses about $150 in parts (some of which you may already have lying around): a DD-WRT compatible router such as the Buffalo WHR-HP-G54, a Hyperlink 2.4GHz 14.5 Yagi Antenna, a cheap tripos, and some screws/velcro.
Construction of this seems really simple, although it is a big too big to carry on business trips to take advantage of nearby free hotspots instead of paying the hotel $15 a night for their internet.
(full instructions at ihacked)
Wifi predator is SICK!!!!
Mine gets Over 10 miles but i use a free hotspot
about 5 miles away for my internet connection
I use it for my XBoX Live or Wii wireless setup!
No Computer even needed!
I found this web site Unreal!
http://www.WiFiPredator.com