Rust-o-leum makes tint-able chalkboard paint. Run to your hardware store and pick some up! It becomes hours of fun-filled entertainment. Between our front door and our dining room was this blank piece of wall that had been crying out for something. Chalkboard paint to the rescue!
Superhero bear and his secret lair!
(Look at how much stuff lives on the back of my front door! Alphabet magnets are the awesome.)
And the beauty part of chalkboard paint is that you don't have to put it on the wall. Paint up scrap lumber. Or rocks. Or canvas (available by the yard at your local craft store). Or picture frames. Or tabletops--how much fun would that be? A table that you can draw ON.