Got an idea that could change the world, or at least help a lot of people? Google wants to hear from you — and it will pay as much as $10 million to make your idea a reality. People are encouraged to submit their ideas, in any of 25 languages, at www.project10tothe100.com through October 20. Entrants must briefly describe their idea and answer six questions, including, “If your idea were to become a reality, who would benefit the most and how?”