Recently, Quasar9 had a picture of a supernova with a ring of glowing gas that looked like a string of pearls that was about one light year across. I compared it to the size of our solar system to try to get a handle on the numbers involved. If you include Pluto, our solar system is "only" about 11 light hours in diameter. Such dimensions are common in astronomy of course, but for laypeople it can be a little mind-boggling to deal with them.
Today I got an email making the rounds in my family with a link to this video from DeepAstronomy . com designed to help get a grasp of the size of our universe using pictures from the Hubble Space Telescope. Enjoy.
If you are unable to stream video, check out the DeepAstronomy site linked above or the Hubble telescope website for still images: HubbleSite