Air Magnet is a very cool commercial product similar to NetStumbler. This product is much more powerful then NetStumbler. Picks up ap's that do not broadcast their ssid. It even picks up ap's on my bus trip home up I-5 that NetStumbler did not find.
Keenan Systems now sells AirMagnet products http://keenansystems.com/store/airmagnet_wireless_network_security_monitoring_products.htm
The AirMagnet spectrum analyzer has just been released it is a 2-5ghz analyzer on a card http://keenansystems.com/airmagnet_spectrum_analyzer.htm
also see Cognio wireless spectrum analyzer http://keenansystems.com/cognio_wireless_network_spectrum_products.htm
