The Leap Motion Controller can be used to drive servos connected to a Raspberry Pi 2:
Visit the blog at Tagenigma.com for source code and more details.
The Leap Motion Controller is connected to a Windows desktop running an HTTP server in Unity to proxy the data.
The Raspberry PI 2 polls data from the HTTP server and then rotates servos to match the orientations from the Leap data.
The video below goes into detail about how the code works: