I just found this site
http://www.googlealert.com. It's a service that performs searches on google for you (you determine the frequency and keywords) and emails them to you. You get an email every time a new site appears in the top 50 results for your search. I haven't signed up yet, but it looks good and they have a free service.
I'm thinking this could be used to track new backlinks, monitor the position of your site, and find out about new competition. Has anyone used this yet, or do you have any thoughts on it?