Designed by gamer shop Meteor, these iPhone 4 cases are supposed to look like the backsides of retro Famicom and NES catridges, complete with warnings on what not to do with the carts. We think they look pretty nice.
What holds true for the Nintendo cartridges (don't immerse in water, etc) also holds true for iPhones. Cheap, these covers ain't, though. One will set you back ¥4,800 (US$57). Who said retro cool was cheap?
iPhone4がファミカセに!? ファミコンカセット（裏面）的な保護ケース登場 [Kotaku Japan]