City-Data.com lists all of the political contributions made by people in your city. For instance, in my city, I found out that only four donations were made to Democratic/liberal/left-leaning causes in the past year, and that three of them came from the same guy.
I know this is public record already, but still, I found it fascinating. I spent a good twenty minutes looking up people I know and seeing what, if any, political involvement they have.