Simply say "take a photo/picture" or "record/take a video" from Google Search, and your camera app will automatically open up, either in camera or camcorder mode, depending on the command it received.
Once launched, just tap the shutter like you normally would. Keep in mind that if you have more than one standard camera app installed, you'll need to select a default on the first time you run these commands.
This is great for those moments when you need to record something quickly and don't want to fumble with opening your camera app. Next time you need to take a photo on-the-fly, simply swipe up from your lockscreen to launch Search, say the command, and snap the picture.
As long as you're on the latest version of Android (KitKat, 4.4.2), these updates should have hit your device already. Of course this will work for all Android devices running KitKat, but if you already have a camera shortcut on your lockscreen (Galaxy devices), this becomes a little less meaningful. Then again, if you're firmly in Google's grasp like I am, this could become your preferred method for quick snaps and videos.