Today, Google announced two-factor authentication for all Google accounts. Previously, two-factor authentication was only available to Google Apps customers. With two-factor authentication, users need both a username/password and a phone to sign-in to their Google account. If you enable this feature, you will be prompted for your username/password like normal. Then you will be prompted for a verification code, which Google will send to your phone. The extra requirement adds an extra layer of security in the event someone steals or guesses your password. Without your phone, your password is useless to a hacker. I like the idea behind 2-factor authentication, but it also means extra work to set-up and log-in.