Over the years our mobile phones have often inherited new features from dedicated point&shoot cameras, things like face-detection, smile-shutter etc have been some of the latest.
In the Sony Ericsson X10 this is taken one step further as the feature face recognition is added, a feature that as far as I know isn’t really that common in dedicated cameras. I would guess that is due to the fact that a dedicated camera is something you use to take pictures or shoot movies – period. You then watch the pictures in you computer, print them or show them online.