The technique is called Back Button Autofocus and once you've given it a try, I doubt you'll go back to the standard old press the shutter half way down focus. The technique of using you AF back button to focus works on both Nikons and Canons and can even be used for continuous focus or single mode. On top of that you don't have to buy any new gadgets or software. It's already built into your existing camera, so nobody's going to make any money off of you!
I have a confession though…when I first tried it I almost gave up and went back to the old ways. It's hard to break years and years of habit but after about a week of shooting, it was second nature, so try it, stick with it for a week or two and see what happens. I've been using Back Button AF focus for 3 years now and will never go back and here's a video by Steve Perry that will describe how it works and how to set your camera up.