I would like to see a voice command to take pictures. How many photos have you seen of people with the out stretched arm trying to take a good photo of themselves. If they could prop the cell phone up and stand back away from cell and take a picture by saying take picture, the world will be a more beautiful place.
My Lucid has a "cheese" shutter.
In the meantime, there's always the timer (assuming your phone has one).
My Galaxy Note II has three words used to trip the shutter. But, like tikibart said, there's always the timer, if you have one on your phone.
Actually a pretty cool idea, better taken up with the manufacturer I would think.
I guess the hard part would be making sure you don't take 3000 pictures of your pocket every time you say the word picture in casual conversation.