Page watching service
In 1997, I started using a service called "Mind-it", which would monitor websites and inform the user via e-mail whenever the contents of those sites changed. Great service, and free, too. In 2002, however, Mind-it shut down. Ever since then, I've been toying with the idea of making such a service myself and making it available to the public (for free, of course).
In January of 2004, I finally got around to doing it and you get to benefit from this. Just sign up for an account and enter URLs of pages you want to watch. I hope you find this service useful. If you do, why not let me know?