kismet
Wireless 802.11b monitoring tool
Kismet is a 802.11b wireless network sniffer. It is capable of sniffing
using almost any supported wireless card using the Airo, HostAP, Wlan-NG,
and Orinoco (with a kernel patch) drivers.
Can make use of sox and festival to play audio alarms for network events
and speak out network summary on discovery. Optionally works with gpsd
to map scanning.