In honor of National Parks Day and the new Ken Burns film that start this weekend, the National Park Service is offering free admission to all 391 national parks this Saturday, September 26. I probably won't be able to participate, but I did the next best thing last night; I spent an hour on the NPS site and read about a few dozen parks. Sure, it's not the same as actually visiting, but it has significantly fewer mosquitoes and poison ivy patches.
If you're not sure where your nearest park is, then this might help.
[via the forums]