WiSpy SSM Tool
This tool is effectively in three parts. The WiSpy SSM Collector, the webservice and the WiSpy SSM Compiler.
This tool is based upon using multiple spectrum analysers at multiple points and using the method of trilateration to determine where a 2.4 GHz signal is transmitted from. Trilateration is similar to triangulation in that you can take three points and find the location of an unknown, but trilateration uses distances instead of angles. Distances can be approximated by recieved signal strength. This has implications in WiFi site planning, discovering rogue access points and also reducing interference sources to improve network efficiency.
Screenshots of the tool in action:
WiSpy SSM Collector
WiFi (802.11b) Channel 1, interference around 2464 MHz.

WiFi (802.11b) Channel 6.

WiFi (802.11b) Channel 11

WiSpy SSM Compiler

Screenshot 1:

Screenshot 2:

Screenshot 3:

Test 4:

Hi Dan, this looks like a fun tool to play with - have you released it anywhere?