The Department of the Interior is offering free admission to National Parks from April 17-25. This covers all 392 national parks, so it might be a great time to plan a little getaway and enjoy a picnic in some nice weather.
For the lazy people out there, just do what I do and have a picnic on your front lawn. Make sure you remember to bring some food though. I sat in the grass for an hour last week before remembering I was supposed to be eating something.