• Introducing ‘Sign-in with Twitter’, OAuth-Style “Connect” « hueniverse
  OpenID is often described as a single-sign-on solution, or “the last username and password you will ever need”. OpenID is a federated authentication protocol – a protocol where users can use credentials from any compatible provider who can “speak” the OpenID protocol. But in this case, not any account will do. Twitter applications need Twitter accounts.
  in Public bookmarks with oauth openid prog security twitter

oauth from all users