I'd consider an OpenID login; I already have one on myopenid.com for Stack Overflow. But I don't like the idea of logging in to a service with any kind of identifiable "persona" where I don't have strong control over the connection. I don't trust Facebook, my Google account is too important to pollute it with random site logins, while I'm afraid a Twitter login would somehow end up giving permission to Twitter DM me, which I don't want.