GamingShogun.com writes: "Like using a key fob authenticator to log into your Battle.net or World of Warcraft accounts? Well now you can do the same thing from the comfort of your iPhone or iPod Touch. The Battle.net Mobile Authenticator v1.0 was released by Blizzard today on the Apple app store for..."
I kind of wish Steam used this.
But one of the Valve devs said that a system like this wouldn't really help much as people who would be willing to use something like this are people who are smart enough to keep their computer secure. Still would be nice to know that your account is totally safe, though.