[lauritz]

While I agree that having one account to rule them all is generally a pretty bad idea if you're talking about projects that deal with sensitive data, I still think it's not that big a deal here. A cookie would tie you to one device, and I really think it is preferable to have this site (which is not dealing with any sensitive information about me whatsoever) not handle an e-mail/password combination, but let GitHub etc handle security. From a UX standpoint, I think this is a good solution that doesn't add too much complexity. If the app dealt with more private data, I would be screaming for a manual login myself.