Not so long ago, it seemed that a projector might become a standard feature on smartphones, like GPS or a camera. LG and Samsung released projector-equipped devices, but many manufacturers - including Apple - have not followed this path so far. If you need a projector in your iPhone though, it is now possible via a dedicated accessory, such as the Pocket Projector for iPhone 4 from Texas Instruments and Brookstone.
The Pocket Projector is basically an iPhone 4/4S battery-equipped case featuring TI's DLP Pico projector technology. Offering 640x360-pixel native resolution, the Pocket Projector displays an image with a diagonal measurement of 50 inches, from the distance of around eight feet (2.4 m). It comes with a 15-lumen LED lamp and a 0.5-Watt speaker located at the back of the case. When the iPhone sits in the case, the projection lens is located near the 3.5mm audio jack. It has its own power source in the form of 2,100 mAh battery charged via a USB cable, enabling the Pocket Projector to double as a back-up battery for your iPhone.