OpenID has had a lot of big supporters, but this week President Elect Barack Obama's Change.gov added the ability for users to log in using an OpenID account and to post comments to sections of the website using OpenID. That's big news and is going to introduce a whole lot of people to the concept of federated identity.
Every other major player that has announced support for OpenID has in fact only allowed accounts with their company to be used as an OpenID elsewhere - they have not allowed other OpenIDs to be used to log in to their own sites. That means Barack Obama is cooler than AOL, MySpace, Google (except for Blogger.com comments) and Yahoo!. Maybe you already knew that, though.
The site uses the commenting plug-in system Intense Debate, which was recently acquired by Automattic, the makers of WordPress. Change.gov isn't allowing comments on every blog post they put up, just on particular pages set up to discuss particular issues. Nonetheless, it's pretty awesome.