I've gotten three links this past week emailed to me about this cool Flash animation.
It's called Scale of the Universe by Cary and Michael Huang. From 10-35 meters (Planck length) to 1027 meters (the 93 billion light year scale of the universe), it allows you to zoom in or out while providing examples of objects of various sizes.
Being egocentric humans, we tend to think the "world" is all that we see around us on a daily basis. What we see and perceive is only a miniscule part of a much, much, much (62 orders of magnitude from small to large) larger universe. And, to make it even cooler, things behave it completely bizarre ways (at least to us) and very small (quantum mechanics) and very large (relativity) scales.
Humans can use a little perspective sometimes. We're less than nothing on a universal scale.