Emily over at the Planetary Society blog has put together a very nice montage of all the objects in the solar system >400 km in diameter to scale (excluding the sun!).

Note that there is a copyright notice so that the people who helped make this awesome graphic can keep track of how it is being used:

I’ve made one version with just the planets, and a second with everything in the solar system that is larger than 400 kilometers in diameter except the Sun, which brings in all the round moons, four asteroids, and more than 100 objects beyond Neptune. By request, I’ve made it in both standard definition and widescreen formats. I put a copyright notice on the poster because I and the people who processed the NASA and ESA images (Bjorn Jonsson, Mattias Malmer, Ted Stryk, and Gordan Ugarkovic) want to find out how it’s being used, so please send me an email. But if you wish to use one of these slides for an educational purpose, our permission is granted in advance.

Also note that you can buy posters of the image at the Planetary Society store! They also have planetary Christmas ornaments!