If you have five minutes and some dinged CD cases—and we'd be hard-pressed to find someone who doesn't—you can make a yourself a mini dry-erase board. Stick 'em on the back of the car to entertain fidgety kiddies, on the fridge to remind your roommate not to eat your food, or by the phone to note down messages.
Or you could Voltronize several CD cases to make a bigger board or even line them on an entire wall. The possibilities, they are endless. ::Instructables