We were one of the first recipients of Droidworx's new retractable landing gear. They were part of a prize package from a contest at MultiRotorForums. Our first impression? They're cool! Once you get beyond the cool factor, you realize that these are well engineered landing gear.
They're lightweight, with extensive use of carbon fiber and aluminum. A Spektrum servo is used for operating the retracts. That servo plugs into your receiver, so you can use a switch on the transmitter to operate them.
Why would you need retractable landing gear? Some camera gimbals can pan 360 degrees (the third axis of a 3-axis gimbal). Some of these gimbals don't have landing hear that turn with them, so you need landing gear that can swing up and out of the way for an unobstructed view. When it's time to pack the copter down, you can pop off the legs via some heavy duty plastic clips.
Once we do some more testing with the copter, we'll attach a camera gimbal to do some filming, but for now here's a short video showing off how the Droidworx retractable landing gear work. The Droidworx XM6 will be a nice addition to our fleet.