A long time ago I posted a series of pictures that were meant to help you keep things in perspective, well this is just as interesting, maybe more so.
This very interesting flash presentation allows you to start at the very small, in fact the smallest anything CAN be, and move up to the largest item, the universe. Each item comes with an item that is smaller and bigger for you to compare the two. Compare a rain drop to a flea, or a proton to a neutron. Fascinating.
PS. use the scroll wheel for some real fun.