Footprints rewrite history of first Americans

Image hosted by Photobucket.comFrom the page:
Human footprints discovered beside an ancient Mexican lake [preserved in ash from a nearby volcano] have been dated to 40,000 years ago. If the finding survives the controversy it is bound to stir up, it means that humans must have moved into the New World at least 30,000 years earlier than previously thought.

The dates have yet to be independently confirmed.