The guys at Headcase have created a pretty cool iPhone case that will probably appeal to anyone who's ever completed Kindergarten. Their officially licensed Etch-a-Sketch case is available for the iPhone 3G, 3GS, and iPhone 4. The case is made of impact resistant ABS plastic that should protect your iPhone from drops and falls (if you still happen to hold it like a four year old).
Sadly though, the case is just a case and doesn't turn your iPhone into a real Etch-a-Sketch. Thankfully, there's an app that does.
The Etch-a-Sketch case is available for $24.99 a