The quad copter scene has evolved at quite a rapid pace since I first discovered a website a few years ago called DIY Drones. They now have 32-bit microprocessors with the math co-processor.... tiny sensors not much bigger than a pinhead that provide 3-axis gyro, 3-axis accelerometer, and 3 axis magnetometer or compass. The software that controls the copter and software tools for adjusting the myriad of settings that control just how rad your copter can fly is state of the art and supported by a huge number of folks that are always improving how it works.
First person view or FPV as it is referred to... is one of the more popular aspects of quad copter or drone flying where there is a camera on board that transmits video back real time and you fly the copter wearing goggles where you see only what the camera sees. It is a bit like virtual reality and you feel that you are actually in the copter flying it. Some of the flying is only possible with the goggles as they fly in places you could not possibly fly otherwise.
The popularity of this type flying has become pretty big and there are a huge number of youtube videos to prove it. I bought a used 250 size copter at the fall all electric fly in down in Woodruff. The 250 means 250mm between the props centers... so they are pretty small and pretty beefy as well... they have to be because this type of flying usually involves all too close encounters with the ground, trees, other copters, often with no damage other than a broken prop. Mine does not have the add ons needed for FPV flying but probably just a matter of time before I bite the bullet and go whole hog. Below is a video shot at an ad hoc race site.