Recreation.gov: This a great site run by…well, I’m not sure, but it’s the federal government in some form. It’s a big database of outdoor facilities and activities in your area. What’s so geeky about that you ask? Well, they have a Web services API: RecML. You can query the database via HTTP and do whatever you like with the results. They just ask that you give them a linkback.
A rare instance of the U.S. governement close to the cutting edge of technology for something other than national defense.