Mozilla's persona project allows for federated login support using an email address as the identifier for a user (and the identity assertion is backed by some clever public key crypto so this should be more secure than any kind of bearer token based federated login system).
Mozilla's persona project allows for federated login support using an email address as the identifier for a user (and the identity assertion is backed by some clever public key crypto so this should be more secure than any kind of bearer token based federated login system).
http://www.mozilla.org/en-US/persona/