I'm currently playing with an Alpha Networks external/outdoor USB WiFi device. It's essentially just a WiFi dongle with an aerial in a waterproof box on the end of a long USB cable. Thus you can position it in a window or up a pole outside to get a connection to a fairly distant WiFi source.
I need a way to find and then maximise WiFi signals, you can't really just use Network Manager as there no easy way to monitor a signal while waving the aerial around.
I have found wpa_gui which isn't very good, I can't get it to scan repeatedly at any reasonable rate. I have also tried iwScanner which is better but is no longer maintained and crashes at intervals, it would be nice if it could scan faster too.
Can anyone recommend a good tool for this job, just needs to allow one to select a WiFi signal and then show its signal strength as a bar which is refreshed reasonably frequently.