Alternatives to User Registration

I’m developing a new Web site and find myself about to create yet another user database. I need people to register with the site so they can leave comments, ratings, submit high scores and maybe get an email newsletter. But I really don’t want to create another registration system. There has to be a better way.
I looked into the OpenID system, but this is definitely for geeks only. Normal people would just get confused over the idea and not understand it. Plus, my attempts to implement it as a test showed that it is not all it is cracked up to be: different OpenID providers seemed to work differently.
I suppose I could skip registration and allow comments anonymously. But that would invite spam. I could allow high scores without registration, but that would invite obscene names. Ratings could be limited by IP address, which isn’t perfect. So I could moderate all comments and only allow initials for high score names. An email newsletter can be outsourced to a service like Aweber.
But are there any more innovative solutions out there?