Why not log into web sites via email without any password?
avinashv: Actually, 1Password, a Mac-only app (I think) that I use reminded me of this.For the unaware, the app basically plugs in to your browser and with a "master password" recalls all your logins. I basically go to a webpage, hit the 1p button and I'm golden. If it's the start of a session, I'm asked to enter my master password and that's about it.Obviously the service doesn't have any control of this, and I am reliant on 1password's security and the security of my password, but it's convenient. I can't see email being the only login because I'd be worried of giving my email password to anybody.