Thinking about all the instant stuff we have on the net I thought it would interesting to watch incoming traffic generated from search engines. I setup a script on a couple test sites that email me the Domain, Search Term, Search Engine and Landing Page whenever a visitor comes from a search engine.
With over 80 sites generating traffic there is no way I could do this on all my sites, but it is interesting and helpful to run on sites where I am trying to get a better feel for the incoming search traffic on a real time basis. I also dump the results to a file to review later, which would be easy to adapt for other things utilizing a database.
Doing a quick search I found this article with a complete tutorial that outlines doing the same. Search Terms Extractor : Statistics and Demographics