VeriSign Personal Identity Provider.

First standalone OpenID provider.  Full featured solutions for both individuals and businesses. 

Technorati is the recognized authority on what's going on in the world of weblogs. We help people search for, surface, and organize bloggers and their daily posts. You can claim your blog on technorati using OpenID.

phpMyID is an Open Source, standalone, single user, OpenID Identity Provider

claimID lets you track, verify, classify, annotate, prioritize and share the information that is about you online.

WordPress plugin to support OpenID authentication for commenting and user registration.

OpenID for comments on Blogger in Draft...

Jyte is a site that allows you to make claims about yourself and your friends, give and receive cred and manage your contacts and groups.

Simple OpenID provider with intuitive ID form of '{id}.myid.net'.
It also Identity management service for any OpenID logged in users as a consumer. It currently provides portable contact list, groups having simple Open API with which any service can check membership, and get member list.
This is the first korean OpenID server also.

OP with imagebased antiphishing solution