Here's a handy new discovery: Check out ReefeRSS if you want to keep track of where visitors to your website are coming from. (Unlike Sitemeter, it automatically converts google urls to search strings, making them far easier to read!) Like everything good on the internet, it's free.
Just for fun, I've used the RSS feed to add a "Last 5 Referrers" section to my sidebar. It's a nice way to automatically reciprocate if anyone links to this blog.
Warning: I do notice some disturbing google searches from time to time. I can remove the display if it gets too offensive.