If you recently updated your iPad 3 to iOS 6.0.1, there's a new feature that Apple hasn't advertised: it includes the same finger-rejection software that is found on the iPad mini. This allows you to hold the device while resting a thumb on the screen without the iPad registering a finger press. It's helpful if you want to hold the iPad with one hand. We have yet to test this function on other versions of the iPad, so if you have an iPad 2, let us know in the comments if you, too, are seeing the finger-rejection feature. We just received the iPad 4 and can confirm that finger-rejection is present. Sweet!
Updat: looks like this might have been a feature of iOS 6. It also works on iPhones. Nevertheless, it's news to us!