VeriSign's VIP (VeriSign Identity Protection) Access for Mobile is a free app that lets you add an extra layer of security to your typical Web log-ins from your iPhone and iPod Touch. Popular sites such as eBay, AOL, GEICO, and PayPal all support the app, which is currently only available for the iPhone. The VIP Access application works by creating credentials that are tied to your iPhone--based on your number--and confirmed through SMS. After confirmation, the app generates a unique, six-digit token that changes every 30 seconds based on an algorithm associated with the credentials created. It's extremely difficult for identity thieves to breach this type of two-factor authentication because the "token" changes frequently and cannot be reverse engineered. As you go about your surfing, you'll use your regular user ID and password, followed by the token generated by VeriSign's app on your iPhone.
There are a couple of drawbacks, though. For one, you'll need your iPhone to be physically available in order to log in. Second, if your iPhone is stolen and contains your log-in and password information, you're in trouble. Yet if you're comfortable with tucking your password information away in an encrypted wallet app, and wrap that in another layer of protection--the iPhone's Passcode Lock and Auto-Lock features found in the Settings app in the General section--you may feel safer sleeping at night. And surfing during the day.