When NASA first started sending up astronauts, they quickly discovered that ballpoint pens would not work in 0 gravity. To combat this problem, NASA scientists spent a decade and $12 billion developing a pen that writes in zero gravity, upside down, underwater, on almost any surface including glass and at temperatures ranging from below freezing to over 300 C.

The Russians used a pencil.

This comes courtesy of Aleah-bug, you can all go blame her. She forwarded it. Evil girl. *BOUNCE*