After reading Simon Willison's post about setting an OpenID, and watching his screencast, I went ahead and set one up. The most attractive thing to me is a unique URI that I can use to log in to a variety of different sites (okay, there isn't much variety yet), without setting up different accounts on all of them. Tim Bray has written a post on his concerns about OpenID, in which he looks at it from the other side, what does an OpenID mean to a site where someone is logging in (among other things). The comments are illuminating. OpenID is not about proving who you are, though that may be built on top at some stage. I'd be very happy to leave comments on Tim's site after logging in with my OpenID, and I don't really care what the OpenID says about me to Tim.