When we first found out that the iPhone 3G may have an additional sensor on it, many nearly immediately began speculating that the device will have a front facing video camera. A lot of contemporary phones have that camera in the front to produce video calls, particularly on European and Asian devices.

It has been revealed now though,

that it is in fact a proximity sensor. The iPhone already has one, but Apple has decided an additional one is in order. Another proximity sensor means the iPhone will be able to recognize with greater accuracy when the device is pressed against your face, or when it accidentally turns on while in your pocket.

[Via iLounge]