Michael Calore, from Wired's Monkey Bites blog, sent me the link to this CNET article, "Yahoo Gives One.org a Web 2.0 Upgrade."  According to the article, the site was revamped as part of "Yahoo for Good Scrum, a company program that lets its employees spend up to three months away from their regular responsibilities to support a charitable cause."

Not only can people add their name in support of the ONE campaign (a ticker on the home page counts as people join), but they can add their face to the Faces of ONE group on Flickr.

They also have a blog and a podcast, which they've had for a while, and now you can add a ONE video via Google video, start a ONE Yahoo Group, and ask a question ONE campaign related questions on Yahoo Answers.

Pretty cool.  I think this may be the highest profile nonprofit-related program to use the social web for social change.