Sharp have developed a CMOS sensor that can calculate the distance between itself and the subject using infrared light. Sadly the resolution is only 320 x 240 pixels, so one for the future then in terms of digital cameras (found via digicamera.net).

“In order to provide these two functions, the company has adopted the Time-of-Flight (TOF) method as the distance measurement technique, in which a distance is back-calculated from the flight time of light. Commercialization is in progress, aiming at home appliances, automotive and security related products as its target applications.”

Website: TechOn - Sharp Develops CMOS Image Sensor Able to Measure Distance to Object