Back in the '90s, the idea of having headlines pushed to your desktop seemed really good, but it never caught on. There's nothing wrong with the basic concept, and it could work better today than with any of those 20th century efforts.
If you do like the idea of choosing a set of websites and having their headlines run across your computer, like a news ticker on TV, there aren't many options to choose from.
It's based on Adobe AIR, it's two years out of date and it can seem a little sluggish — but of all the options out there, this is the slickest ticker I could find. It works with Google Reader and it can be positioned on any side of your monitor or pushed to a second screen, if you're using more than one.
If anyone knows a better one, let us know! Or go make one!