Apple has unveiled a voice-controlled organiser app dubbed Siri which is one of the headline features of the iPhone 4S.

Launching in beta with the new iPhone, after firing up Siri you can just ask the iPhone questions and it will answer them on-screen.

Apple's Phil Schiller and Tim Cook took to the stage to demonstrate Siri at the iPhone 4S launch in California.

Talk to me

They asked, "What is the weather like today?" and instead of looking out of the window, they looked at the iPhone 4S, on which Siri had pulled up a weather report.

More examples included Schiller telling the iPhone to set an alarm for 6.30am the next day, to find a Greek restaurant in Palo Alto, to check his calendar and to set up appointments.

Siri

Image credit: This is my next

What's nice is that it understands context – you might ask it to make an appointment for you at a time when something is already scheduled, in which case it will tell you and ask if you want to move the existing appointment.

Siri is integrated with apps like Maps, Calendar and text messaging, so you can now dictate messages and emails, as well as any other text – whenever you see a keyboard on the iPhone 4S, you'll also see a microphone icon.

Let's get siri-us

The demo, which lasted a fair amount of time, also revealed a hook up with Wolfram Alpha, which means you can ask all manner of trivia questions and get the answers from Siri instead of Google.

Apple reckons you should be able to simply use your natural language – although we'd like to see it try and cope with a thick Glasweigan accent – and there's support for English, French and German.

Working over 3G and Wi-Fi, you'll see the Siri beta on the iPhone 4S when it launches on 14 October.