Bill Stone's talk at TED has been posted and it is very inspiring!
Bill Stone: Journey to the center of the Earth ... and beyond!
Bill Stone, the maverick cave explorer who invented robots and dive equipment that have allowed him to plumb Earth's deepest abysses, explains his efforts to build a robot to explore Jupiter's moon Europa. The plan is to send the machine to bore through miles of ice and swim through a liquid underworld that may harbor alien life. And if that's not enough, he's also planning to mine lunar ice by 2015.