I feel a little freer to be a goofball when it comes to cases for my Nintendo DS, since the device, as opposed to a cell phone or a BlackBerry, is not really a professional device. I don't have to be as reserved with it, whereas with my BlackBerry, the most outrageous I go is a brightly-colored gel case.
Which is why I'm nothing but charmed by this Monster DS Case! Available on Etsy for $20, the monster "eats" your device. I'd love to pulls this out on the bus, and I would definitely always say "NOM NOM NOM" when I see it, just like the seller describes it!