The Size of Space is an interactive site by Neal Agarwal that takes us through the relative size of heavenly bodies from an astronaut to the observable universe. Considering some of the objects that fall in between, we can bet that the observable universe is a lot bigger than it was even 50 years ago ("observable" being the growth factor).
While you might not be amazed at the relative size of the planets, you will learn something new. There are moons in our solar system that are larger than some planets in our solar system. We know about at least one star that is smaller than Earth. And how astronomers have mapped out the larger universe is pretty impressive. -via Boing Boing