Augmented Reality is the coolest thing. Imagine holding up your phone to an object in real world and your phone will give you info on that object. It could a bus stop and your phone could tell you about what time the bus will arrive.
It looks like Apple wants to join the party by releasing some augmented reality apps in September when it updates the iPhone with OS 3.1. The down side about this is that these apps will be available only from iPhone 3GS which uses the compass. But don’t fret, the technology is also coming to Android phones so be on the lookout.