Discounts available for the GoPro Combat Cage and Zip Tie Lens Gears available at WideOpenCamera.com. A cage on a little GoPro might sound funny, but it adds several mounting points when working on something like a Car or Motorcycle Mount to prevent weird jello footage (GoPro is pretty bad at this).
The Zip Tie gears are still by far the best low profile lens gears on the market if you plan to use your lenses with a Follow Focus system. They can be cut down to fit any lens and reused with simple zip ties. For more information about these products, check out the product page.