> This sounds less convenient, harder to implement, and no more secure than OpenID

In what way is it less convenient? A standard user has their phone with them...24/7? At least in the sms realm it's more convenient than trying to come up with a password that has: A capitol letter, a number, a special character, a lower case letter. Also way more secure, a user gets sent a message of a one time code looking like 037.820.374.839 the time it would take to guess that, the one time code would have been timed out and the hacker would have been no closer to getting in compaired to a static password.