Feed43 lets you do advanced screen-scraping on any web page, meaning you can get only the information you're interested in whenever it's updated. Be warned, however: This is not for those who are afraid of HTML. To create a feed with Feed43, you have to tell it which parts of the HTML source to look for and how to use it. It's very powerful, but not for the lazy. If you want to see what's involved in creating a new feed, the Feed43 blog has a couple tutorials, including one that shows how to get a feed for the weather from Weather.com. Right now Feed43 is in private beta, but signed up and get an invite.