And Apple has updated its own apps to take advantage of the bigger display -- the iCal app has a new five-day week view in landscape mode, for example.

The device also includes a new technology, wideband audio, that's intended to make voice calls sound more natural.

And the new phone gets a new OS, iOS 6. It has better mapping, with turn-by-turn directions and sharper satellite imagery. The Safari browser will have full-screen mode, among many other improvements.

An upgraded camera has an 8-megapixel sensor with a five-element lens and a faster f/2.4 aperture, which should give better low-light photography. A "sapphire" cover protects the lens and gives sharper pictures.

The new iPhone adds 1080p video with better image stabilization and the ability to capture stills while recording video.