Your local wireless network, or your "Personal Area Network" may not be so local or personal after all. Two devices demonstrated at the "DEFCON" conference in Las Vegas radically increase the range of Bluetooth and WLAN connections.
The "BlueSniper rifle" is a high-gain, directional antenna for BlueTooth which has been successfully connected to a Nokia 6310i phone at a distance of 1.1 miles.
The Sniper Yagi has a claimed range of 15km for wireless networks.