Disable Login in WordPress

One of the reasons that make switching to Octopress so appealing is the security. There’s literally none needed because there’s nothing to hack into (besides your box, but that’s another story). So, I stumbled upon the wordpress OpenID plugin, which is very promising. However, now I’d like to just disable password logins now that I have that. Is this possible? Or, can I edit the db to set an empty password? Would that disable logins with a password?