Like the prize inside a Crackerjacks or kids' cereal box, Siri, Apple's voice-controlled digital assistant, is the raison d'être for buying an iPhone 4S, especially if you already own a 4. A cult of personality has already arisen around Siri. Numerous bloggers have cited her snappy answers to stupid questions, such as "What are you wearing?" "Where can I hide a body?" "Open the pod bay doors," "Will you marry me?" "What are you wearing?" etc. But I hope you aren't thinking of buying an 4S just to get a really fancy Magic 8 Ball. Siri does a lot more than wittily answer esoteric questions. She could represent the first true user interface paradigm shift since the iPhone and its capacitive touchscreen, and perhaps since the Mac and the Graphical User Interface 27 years ago. And like any paradigm shift, Siri will change how you behave, and introduce a whole new set of social rules of engagement.

The iPhone 4S is officially out today in stores and naturally, everybody who's picked one up is putting it through tests. Here's a video showing just how much better the iPhone 4S's video recording is than the already great iPhone 4's HD video recording.

Some iPhone 4S reviewers with early access are doing what anyone surely will once they fire up Siri: ask Apple's hotly anticipated personal assistant a lot of weird things. And rather than replying with a generic error, Siri can come back with a lot of equally weird and clever responses.

The first performance and graphic benchmarks for Apple's iPhone 4S are out. Even clocked at about 800MHz, its dual-core A5 processor is still faster than every major smartphone alternative running Android. Now that's fast.