When we were thinking about things that we could do for this year's fund raising campaign, we realized that one thing that might be cool would be to try giving people a creativecommons.net OpenID with their donation. Because donors authenticate their identity with us to the extent that they pay us money and because Creative Commons is a somewhat known entity, we thought this might have some value. In addition, an OpenID profile on creativecommons.net would allow us to test some ideas that we have about how a copyright registry might work.
If you want to try it out, join the network by donating to Creative Commons.
Registering your works will give you this nifty extra bit on your CC deeds.
Then you can use creativecommons.org/yourname to login to any OpenID site.