WashingtonWatch is a site that summarizes legislation pending before Congress, and allows user comments on each piece of legislation. The site is nice and clean, and the explanations proposed laws are clear and understandable.
The home page lists all the legislation currently pending, but grouped by tabs for categories such as: Most Popular, Newest, Greatest Cost, and Greatest Savings. If you click on a proposed law it will take you to a page where you can leave a comment about the legislation. Also, users can edit the section that describes why the legislation should or shouldn’t be passed. Sort of like Wikidpedia, except probably with more controversy as the site becomes more popular.