A few years back I wrote about Nicola Tesla and his Wardenclyffe Tower building. That site is now for sale and Matthew Inman is trying to raise the money to buy the site and to start a museum dedicated to Tesla. If there is one thing you need to do today that is donate to this fund!
Update: As of a few days ago they reached their target to buy the site but there are still some days to go and they need all the money they can get to get the museum up and running. (via)