Kitchen Dial has touch-free mode

Kitchen Dial, a simple iPhone application that converts things like quarts to cups and vice-versa, has a touch-free mode where you can tilt the iPhone in different directions to make your selection. This way you don't have to smudge your iPhone screen with cookie dough.

Instapaper ships with a tilt-scrolling feature that, rather than scrolling with your finger on the glass, lets you scroll the article you're reading by titling the iPad.

I wouldn't mind seeing other apps with features like these.