Hi Philip and everyone,
I am a big fan of this site and forum, and hope you don't mind if I share info about a website I created, VeryRelated.com. It uses the Yahoo Search API to calculate how words are related on the internet and displays "mind maps" showing how words are related and their popularity.

I made a short tutorial video explaining how the site works, and posted it on Youtube:
http://www.youtube.com/watch?v=0oScDRq4RG4

The site is:
http://www.veryrelated.com

cheers,
Geoff