Windows Live now became an OpenID provider, the release is meant for a technology preview and users are advised to wait for the final release to use Windows live ID as OpenID.
The Windows Live ID Provider enables anyone with a windows live ID account to setup an OpenID alias to use at OpenID supported web apps.
To use it go to and use the sign-up button to set up a Windows Live ID test account in the INT environment. Go here to set up your OpenID test alias. These are test accounts and may not be permanent accounts.
Microsoft is late on the party, Yahoo and Blogger added support for OpenID in January.
Honestly, is anybody actually using OpenID yet?