#8) NetStumbler
NetStumbler is a wireless networking tool. It supports Windows OS. It makes use of 802.11b, 802.11a, and 802.11g WLAN for the detection of wireless LANs. It also has a trimmed-down version called MiniStumbler that is for handheld Windows CE OS. It provides integrated support for a GPS unit.
NetStumbler can be used to verify network configurations, find locations with poor coverage in a WLAN, detect causes of wireless interference, detect unauthorized access points, etc.