I just bumped into this post by Martin Atkins that talks about proxy OpenID services that can delegate OpenID formated requests to their respective browser based authentication identity providers.
I’m actually working on such a thing that will delegate OpenID to Yahoo’s BBAuth authentication allowing anyone with a Yahoo ID (and, of course, anyone with Yahoo Email) to authenticate using OpenID.
The only annoying thing is that the URL is a bit ugly. Currently, my version uses a URL structure of /users/john@yahoo.com which is a bit annoying, but should be sufficient for now.
I’m hoping to get a release sometime next week. Stay tuned!