Free WiFi Scanner from eEye Digital Security
It seems to work fairly on my Dell X50v, detecting the network at my house. But I don’t live in a heavy WiFi area (so some driving will needed to test further). It even has a “blute” (brute?) forcing crack (which I will try a little later).
If you have a chance to try it out on your WiFi-enabled device, let us know what you think!