A useful tool to get a rough estimate for how many times a keyword gets searched on google a month.

http://www.technobloggie.com/googleSearchEstimates.php

I don’t know how accurate it is but it might provide you with another reference point to contrast with overture search counts.

The same guy offers some other tools as well:
http://www.technobloggie.com/password-protected-rss.php – How to password protect your feeds
http://ww.technobloggie.com/ping-yahoo.cfm – A tool to ping yahoo.