One features a slide out keyboard.
According to a Taiwanese Mac site tw.apple.pro, Apple is currently testing three variations of the next iPhone.
One of the three iPhone prototypes features a slide-out QWERTY keyboard, while the other is an spec upgrade over the iPhone 4 with a longer lasting battery and 8 megapixel rear camera. The third prototype is unknown and it could be anything from a button-less, touch-based 4″ iPhone 5 to a smaller, cheaper iPhone Nano.
tw.apple.pro do have a credibility of accurately predicting Apple announcements. They were bang on about the white iPhone 4, iPhone 4′s battery, 2008 MacBook redesign, the new multi-touch iPod nano and the 2008 MacBook Pro’s unibody. However, of course, despite a good track record, the site need not be completely accurate. Take it what you may.