I'm hoping that we'll be able to catch Jupiter at some point and get a glimpse at some of its planetary bands (though our western horizon is somewhat obstructed and the gas giant, Venus, and Mercury are visible near the horizon this month; see Earthsky.org). I remember seeing a few of Jupiter's bands when I was a kid and the Great Red Spot has been a source of conversation for Conor and me since he knows that it's basically a giant hurricane (and post-Hurricane Sandy, he knows what that is as well) that's been spinning for centuries. It's hard as a human to imagine scale on a planetary level, so when I tell him a few Earths can fit in it, I'm not sure what he thinks, but regardless, it's a cool comparison.
For incredible comparisons if you happen to live in the NYC area, the American Museum of Natural History's Rose Center for Earth and Space has a great "Scales of the Universe" exhibit which puts things into perspective, literally. It uses the planetarium globe as a centerpiece in explaining the relative sizes of all kinds of things in the universe, including planets, stars, even particles. It's pretty amazing when you think of our sun (into which you can fit anywhere from 1 million to 1.3 million earths depending on how you get them in there — a great breakdown of the question from Cornell's "Ask a Scientist" here) as teeny compared to other stars. In fact, scale in general, especially in terms that kids can understand (in comparing balls of different sizes for example) is really helpful when trying to explain planets and size, even to yourself! The Large Picture Blog has great comparison graphics on the solar system and about 3/4 of the way down on the page, it has an incredible graphic of the relative sizes of stars in the universe.