Siri, the "artificial intelligence" personal assistant was one of the highly circulated rumours that came true at Apple's new product launch tonight in California.

Siri takes voice commands to answer any question and can coordinate answers so they relate to each other. For example, ask for the best Indian restaurant near you, a table at 7pm and then ask for screenings of your favourite film, and it will show you timings for the film which start once dinner is finished; in a convenient location to boot.

Apple acquired the Siri app back in 2010, and has not released it on an iPhone until now.

Siri will be central to the iPhone 4S experience and will live behind the "home button" for easy access.

Here is a video of Siri in action uploaded to YouTube by Techcrunch back in 2009: