On our recent show, Outta This World, Seth takes us out to the parking lot to demonstrate how far away certain objects are from our Sun. In his example, the sun is represented by a ping pong ball.
Fourteen feet away from that ping pong ball stood Molly, representing the Earth; seven feet beyond that stood Keith, representing Mars; beyond that you can see me, portraying Jupiter; and far outside our parking lot, buying a creamsicle, is Jay, playing the part of Voyager 1.
Ready to build your own solar system? Here are the relative distances of various objects, assuming your sun is a ping pong ball. Included are the star 51 Pegasi (parent to the first discovered exoplanet, Bellerophon) and the stars recently surveyed by the Kepler mission.
Another interesting way to build your own solar system is with Aurora. This is a game in which you can evolve your own solar system, and populate it with living things. Because the SETI Institute looks for life beyond Earth — both intelligent and otherwise — we thought this was an interesting and fun way to confront some of the factors that govern whether planets are suitable for life. Seth also wrote a small blurb about the work of the Institute that you can find as part of the documentation for Aurora.