The idea: Use your smartphone to log into websites and supply credentials via NFC or SMS.

Examples: Google's NFC-based tap-to-unlock concept employs this. Instead of typing passwords, PCs authenticate against the users phones via NFC.

The good: It should be as easy as it sounds. No interaction from the user is needed, except any PIN they might use to secure the phone itself.

The bad: Getting websites to play along is the hard part, since password-based logins have to be scrapped entirely for the system to be as secure as it can be. Existing credentialing systems (such as Facebook or Google login) could be used as a bridge: Log in with one of those services on your phone, then use the service itself to log into the site.