To celebrate their 10th birthday, the 'do no evil' guys over Google have just announced a new initiative: Project 10 to the 100th (or 10100). It's aim is to find THE idea which will help the most people, which Google will then support with £10m investment.
Great idea. Though I do wonder whether supporting lots of little ideas (in a micro-finance way) might actually have more impact than finding one big idea to champion.
(Thanks to Faris)