flow|state: OpenID: Great idea, bewildering consumer experience
A great article on some shortcomings of OpenID from the perspective of a new user. Some of these can be resolved by site owners ('consumers' in OpenId-ese), others require a bit of input from the OpenID foundation. Some great observations, generally geared towards making life easier for new users.
http://miksovsky.blogs.com/flowstate/2007/08/openid-great-id.html