Stack Overflow is obviously a great example of really successfull implementation of OpenID, but let's be honest - it's a little easier when your target user base is geeks like us! I'm really interested to hear people's experiences of implementing OpenID outside hi-tech websites.
What kind of responses have you got from
- a) users?
- b) statistics?
with regards to the user experience of OpenID 'login with..' login systems?