So I was just about ready to hit the sack as I placed my iPhone 4 directly on top of my iPad. Both were on their homescreens when all of a sudden the iPad starts bugging out. It was as if I was swiping from page to page on the iPad and even an app opened up by itself. I'm sure it has something to do with the iPhone's external antenna. Give it a shot, you'll have to play around with it a bit to replicate the effect.