It's a well-done site that clearly and simply lays out the problem OpenID is trying to solve, discusses how you can get an OpenID (and has a great discussion about what to look for in an OpenID provider and things to think about in choosing one), and shows you typically go through the OpenID login process.
It's not a new site.. it seems to have been around for a while... it's just one I hadn't come across in my various writing about OpenID and identity issues (scroll down a bit to get to the OpenID posts).
I particularly liked this graphic, as it so nicely captures the intent of using OpenID to reduce the number of user account info you have to remember (click on the image to go to the page with the full-size version):
The site does need a couple of very minor updates... for instance, the link on the text "over 27,000 OpenID-enabled sites" takes you to a place on a Wikipedia page where whatever list may have been there seems to have been removed. The "Use" page also embeds Simon Willison's much-referenced OpenID tutorial video from 2006, which is a great introduction video - but unfortunately the example site it references is WikiTravel and when I tried logging in there several times with OpenID I was unable to create an account on the site.
Regardless of those minor nits, it's a well-done site and one that is a good resource if you are looking to learn about how OpenID can potentially help you.