ChangeNotes
ChangeNotes is a service that tells you when a site has changed. You register on the site and then enter the websites that you want to monitor. Then you are sent emails when the site updates. This is a slick way to stay informed of changes on sites that don't have RSS feeds. However, I have tried several of these services and they seem to be hit and miss. If you register a site that updates its date on its page every day, that often counts as a change. Even worse are the ones that get new ads every day and then you get an email informing you about that. Just something to be aware of when selecting sites to monitor.