Besides opening up the camera application and activating the shutter, voice command could also allow users to keep or delete a particular snapshot. The patent application was filed by Microsoft back in 2011, although the USPTO is just bringing it to our attention.
Part of the application includes a training period to let the technology "learn" your voice and the mannerisms of how you speak for improved accuracy. In addition, users could replace a default phrase with another command. For example, "take picture" could be changed to any rarely used phrase to prevent the taking of an accidental picture. Besides a human voice, a particular noise like clapping hands can be set to fire the camera. We wouldn't recommend that setting for those with the Clapper (Clap on, clap off).
Microsoft patent application for voice control on a mobile phone camera
source: PatentBolt via WPCentral