Here's a cute web toy that doesn't give you time to fool around! Sandcastles is where you build castles in a hurry, because the waves are coming to get them. But that just gives you a clean sheet of sand to start over with. Or, if you are so inclined, you can just watch the waves go in and out, or listen to the sounds of the ocean while doing something else. On a real beach, you'd learn quickly to build your castles further up the beach -just not too far up, because wet sand is heavy to carry. -via Boing Boing