Nike is attempting to accomplish the goal of having 1 Million runners participate in the Nike+ Human Race on August 31st. There are 25 cities participating, and runners who arent near a participating city are encouraged ro register for the event and run using the Nike+ system. They can then upload their data to become one of the "1 Million".
There are two charity elements to the race: Nike claims money is raised for each mile you run, and you also can do fundraising through the site when you register for the race. I am not too sure how all of that works, and the site info isnt clear. Perhaps when you register you get more info?
If you live in one of the cities the events take place in, there is an added bonus. The 10K finishes with a concert ... and in Chicago its Fall Out Boy :)