One of the smaller features I have appreciated in the iPhone's camera app has been the volume up key acting as a shutter release. Instead of tapping on a digital button, pressing the volume up key will snap a pic.
When I first launched the Camera app on the BlackBerry Z10, I instinctively pressed the volume up button and to my surprise it snapped a pic. The normal method for taking a picture on BlackBerry 10 requires you to tap anywhere on the screen. But with either volume key acting as a shutter release, you can avoid tapping on the screen altogether.
Unfortunately I wasn't able to use a pair of headphones (I tested both the Apple EarPods and the pair included with the Z10) as a remote shutter release. Hopefully this is something that can be added in a future OS update.
If you're curious as to how BlackBerry 10 works, be sure to get a glimpse of it on your iPhone or Android device.