I've tried integrating sfPHPOpenIdPlugin but that hit a dead-end since it's built for Symfony 1.2 and relies on deprecated PHP functionality; I also had a go with sfGoogleLoginPlugin which did authenticate correctly but lacks extended capability to retrieve user details (+ would restrict me to Google; obviously).
I'm thinking the most viable solution is to link in one of the various PHP libraries available into my model.
I'm wondering if anyone else has had any success/tips with such an integration and what libraries to consider?