I used to use Netstumbler to configure wireless networs, especially over longer distances with high gain antennas. But since I switched over to Linux I've missed Netstumbler's great histogram feature.

So I brushed up my scripting skills and wrote Scanmeter, a very simple to use bash script for directional antenna pointing. Anyone who wants to give it a whirl or improve it here you go:

http://www.skifactz.com/wifi/Linux_Antenna_Tuning.htm