OpenID is a great way to avoid forcing people to remember yet another login/password and means we wouldn't have to worry about people forgetting their passwords etc. More and more sites are using it and a lot of people already have one via another service (eg Yahoo!, Flickr, etc.)

There is a bogpost about confluence support of OpenID here: http://blogs.atlassian.com/developer/2007/02/_with_the_recent_press.html

OpenID support would be great for confluence instance that allow registration/login of public users. This support should also be integrated with confluence instances that delegate logins to crowd.