Insider Apple sources are reporting that the company is hard at work on an iPhone with a slide-out QWERTY keyboard and even has prototypes currently on show.

Said to be aimed at the enterprise market, it's thought to be the one missing feature that could mean the iPhone sees wider business world acceptance.

Newswireless.net says that reports from inside mobile operators suggest Apple is "canvassing" the idea with operators, along the lines of: "If you had a keyboard version, how many would you take?".

Actual prototypes are said to have been sent to senior executives inside the operators, although the keyboard on these early models is said to have "'issues' which are not yet resolved".

These same sources apparently say that "they are definitely expecting to see one [QWERTY iPhone], aimed specifically at corporate buyers, around this time next year".