Looks like face detection is going to be this year's larger LCD -- the big(ish), new(ish) feature that makes this year's cameras better(ish) than last year's.
In the beginning, back in the 90s, there were digital cameras, but the resolution was rubbish -- so when manufacturers wanted to make this year's camera better than last year's, all they had to do was add more pixels. Eventually the sheer ubiquity of pixels (5 million, 6 million, 7 million, more) made them less exciting, so the focus moved to making digital cameras smaller, slimmer and more stylish. Then we moved into the bigger LCD phase, which ran out of room when the screens got almost as big as the back of the camera. Now there's nothing to compete on except features, and face detection looks like the flavour of the year.
Fujifilm launched several cameras with face detection last autumn, including the Finepix S6000fd. Now Canon has announced the Digital IXUS 70 and IXUS 75, with face detection; Samsung has launched the i70, with intelligent face recognition technology; and Pentax has announced the Optio A30, with face recognition AF and AE.
All these cameras look for faces when you frame a photograph and optimise the focus and exposure accordingly. If you've ever snapped a picture of two blurred people in front of a perfectly focused wall, you'll know autofocus doesn't always have all the answers -- and you've probably also learnt to point the camera at one of the people, press the shutter button halfway down to lock the focus, and recompose. Now you avoid the effort of firing all those neurons in your brain by letting the camera whizz some electrons round its circuits instead.
Is face detection useful, or would you rather control the focus point yourself? Type your answer into the comment box below.