A few months back I registered for the Technorati Developers’ Contest with a vague idea of a tool to help people track blog conversations about bills currently before various legislative bodies.
I never got myself organised enough to build anything, but it seems other people had similar ideas. They actually got as far as refining those ideas and implementing them rather effectively.
Check out the winners here (contrary to some expectations, I suspect this will be of interest to at least a few non-techies).