is a wireless device monitoring application that allows you to watch signal and noise levels, packet statistics, device configuration and network parameters of your wireless network hardware. It should work (though with varying features) with all devices supported by the Linux kernel.
great for at-a-glance monitoring / tshooting WiFi connections and WiFi adapter (tx/rx power & rate)
best feature: signal histogram which seriously eases the process of determining AP’s physical location when using a directional antenna
(my 2 cents)