zmjezhd's mention of Wikipedia in another thread reminded me of this: Citizendium.
Here's the topic: When you're a cofounder of Wikipedia, what do you do for an encore? If you're Larry Sanger, the answer is simple: you build another Wikipedia. A better one.

I presume most of you have heard about it. It is now up, in beta version. Here's the link, if anyone wants to get in on the ground floor, so to speak:
Citizendium beta.

Disclaimer: I am not advocating Citizendium; just proffering news, since it hasn't been mentioned here.