The world doesn't need another website. But www.bigthink.com seems to have some promise. I read about it in The New York Times this morning. You can read about it here.http://www.nytimes.com/2008/01/07/technology/07summers.html?ref=technology
Basically, it is meant to be "a YouTube for ideas."
It's too early to really know if bigthink.com is worth a time investment. But I will tell you this--they need to do some work on their production. Their five minute introductory was sloppily edited and typographically crappy. Not a professional image for what could be an important site.