Apple today seeded iPhone developers with iPhone OS 3.1 Beta 3, termed Build 7C116a. Apple also released a new version of the iPhone SDK 3.1, Beta 3 (Build 9M2808). Both downloads are available to registered developers through Apple's iPhone Dev Center.
Apple seeded the previous beta nearly two weeks ago, and it remains to be seen what new changes are present in the third beta version.
Apple is reportedly relying on new developer tools present in iPhone OS 3.1 to deploy augmented reality applications that are capable of overlaying live video from the iPhone's camera with real-time data.