Wardriving is searching for Wi-Fi wireless networks by moving vehicle. It involves using a car or truck and a Wi-Fi-equipped computer, such as a laptop or a PDA, to detect the networks. It was also known (as of 2002) as WiLDing (Wireless Lan Driving, although this term never gained any popularity and is no longer used), originating in the San Francisco Bay Area with the Bay Area Wireless Users Group (BAWUG). It is similar to using a scanner for radio.
Many wardrivers use GPS devices to measure the location of the network find and log it on a website (the most popular is WiGLE). For better range, antennas are built or bought, and vary from omnidirectional to highly directional. Software for wardriving is freely available on the Internet, notably, NetStumbler for Windows, Kismet for Linux, and KisMac for Macintosh.
Wardriving was named after wardialing (popularized in the Matthew Broderick movie WarGames) because it also involves searching for computer systems with software that would use a phone modem to dial numbers sequentially and see which ones were connected to a fax machine or computer, or similar device.