Have you ever been to the planetarium at the Natural History Museum in New York? The museum is probably my favorite museum ever, and obviously the planetarium is cool (A. its a planetarium and B. this guy runs it,) but did you know the whole display design outside of the planetarium, as you're walking up, isn't just pretty hanging sculptures of planets? Its really an exhibit that attempts to explain how large the universe is. (So next time you're there, resist the urge to run up the ramp and leave some time to go through the whole thing.) And it does a great job of it. But still, its just so hard to understand. To grasp. Don't you think?
I came across this series of illustrations (one above,) on some cheesy website that does a great job of it as well. So click away if you need some perspective. Or to just join me in nerding out about space stuff.