Legal advice, iPhone App YouTube Shit?

YouTube is an Internet phenomenon Shit. I have a free application soundboard in the App Store (yes, I'm $ 99 in the developer program). I was wondering what the legal ramifications would be. I could call the application YouChewPoop, perhaps, after the Web site. I can not use the words Mario, Luigi, Zelda, etc.. Because they belong to Nintendo. How do I go on Naming the application and the advice of his. Perhaps instead of saying I could spell mar0 Mario, I do not know.

If you do use it you have a warning to let the user know that these names belong to the corporation and not you. You would probably need permission first though.

Zelda’s Lullaby on the Ocarina for iPhone