Good for absolutely nothing except a giant time suck, yooouuutuuube.com will take a video you chose and make it fill your screen. Alternatively, you can let them pick a random video to jigger with.
Yooouuutuuube.com requires a good Internet connection, updated flash and, of course, a decent computer. Don’t try this at the airport on your phone.
To create the video mosaics, pick your favorite YouTube.com clip and play it this way.
There’s no way to embed yet, but try it out with the video below.