Gloved Hand for Airplane control has the most engineering cooperating as a System, so I found it most impressive, and give it my vote. I was impressed with the 'bend-sensor' affecting the RPM of the motor; I never saw one of those before.
Overall, "gesture" controls have been on the drawing boards for at least 10 years or so, but I still haven't actually seen one fully characterized for real-use, (like in the movie, "Minority Report" from 2002).
Yes, Jenn, it is another tough choice. I think readers are going to be surprised by ahe amazing variety of gadgets we've presented over the past year. They range from the wildly whimsical to the straight up practical.
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.