Looking for some "did you know" factoids to debunk?

I write stuff for a podcast (imaginary friends) and I am looking for some factoids to bust. The first one I did was "if all the people in china jumped in the ocean it would cause a tidal wave". I did the math and worked out the sea level would rise by 0.2 nanometres. So if you know any more of these can you please write them down.

Anonymous2010-05-09T19:49:07Z

Favorite Answer

People only use 10% of their brains. Actually, people use all of their brains.

?2010-05-08T16:41:18Z

How about the one where supposedly the Moon is exactly the same size at the horizon as overhead. Simple refraction would account for both a slightly larger size, and the oval appearance of the image.

Anonymous2010-05-09T16:36:31Z

" Walking under a ladder will bring bad luck".