Yahoo Developers Network pubbed a research about their openid usability, I just wanna highlight these 2 pages:
user exposure to multiple(13) openid providers
Just silly, they had already to insert the multiple providers, so, why not instead add some logic to that form so that you just need to type in your openid url/email? Code does the rest.
OP & RP collaboration
Agree if we want to have an homogeneous experience.
