Yes, but as of now there is no punishment for letting others borrow your oauth token. So just publish your oauth and let anyone use it to sign up for services.

Yes, but as of now there is no punishment for letting others borrow your oauth token. So just publish your oauth and let anyone use it to sign up for services. It may get tricky if sites limit registration to unique keys, but so long as it's purely checking with a third party and not storing your info, they're shouldn't be a way to validate an id is used more than once.