I love two factor auth, but I don't like that it uses my phone number. I really wish I could buy one of those RSA SecurID two factor auth key fobs from any hardware supplier like NewEgg and just register the serial number of the device with Google or any other company I want to use two factor auth with.

Even better would be to allow me to register backup two factor auth key fobs and I can just throw one or two backups in a safe deposit box, safe or similar safe place.