...and then we have...

Air Writing: Next Big Thing in Cell Phones?

"Forget fumbling with tiny cell phone keys. A prototype of a new application allows cell phone users to write short notes in the air and send them automatically to an e-mail address.

This represents just one possible step toward allowing people to naturally merge the real world with the information power of the Internet. Travelers and other mobile users could air-write notes to themselves rather than have to text on the run.

"By holding the phone like a pen, you can write short messages or draw simple diagrams in the air," said Sandip Agrawal, an electrical and computer engineering student at Duke University in North Carolina."

Full article here.