Re: Diretional antenna
http://www.unwiredadventures.com/unwire/2005/12/defcon_wifi_sho.html
125mile (~200km) unamplified 802.11b link (with massive dishes), and that was in 2005 or so.
Not practical for potential bomb detonation, but goes to show how far you can throw a standard wifi link. If you wanted to use amplifiers, altered frame timings and really get into tweaking it, you can get it even further (the GP wiki post lists notable links that are longer than the above).
Biting the hand that feeds IT
