Before I even had kids, I started painting my guest room in a star/night-sky theme because I am really, really, REALLY nuts for outer space and all things star-related. Like the "all-I-ever-wanted-to-be-was-an-astronaut-ever-since-I-was-a-little-girl" sort of obsession that has just grown stronger with time. Since I couldn't name my children after stars (I dunno--Moonbeam Stardust does have a nice ring to it!), I settled for naming my ferrets after stars: Castor, Pollux, Sirius, Betelgeuse, and Vega. Turns out, near the end of painting my guest room, I found out I was six weeks pregnant with my first child and quickly turned it into the baby's nursery. Three children later, this nursery has been the perfect room for both my girls and my boy to grow up in. It has a non-babyish quality to it that will allow my 3-year-old son to stay in it until his teenage years, when we can add a cool metal desk made out of tool chests topped with a laminate counter, pushed up against a metal bulletin board on the wall.
Oh, and the best thing of all about this room: GLOW IN THE DARK accurate representation of the night sky! That was a must for this room, because how can a star/night sky themed room NOT have stars and planets that glowed in the dark when you shut the lights off? Another positive feature of this glow-in-the-dark room: no need for a night light. My children have never needed a night light in this room, since the stars glow brightly when the lights are shut off, and then dim over time to complete darkness by the time they fall asleep.