This is a project that a colleague and I have been working on. It's called the uMotio. It's basically an arduino (tm) with gesture control built in. It picks up x,y and z motion and also has built in gestures such as swiping left/right/up/down and even airwheel (clockwise and anti-clockwise).
The board contains a gesture control ic along with an atmega32u4 (used in the arduino leonardo). It has an arduino compatible bootloader on it and we also created an arduino library for it to make it easy to use.
I've been demoing it at BinarySpace meetups the past two weeks and the guys have been playing games with it (- YouTube).
In its current state (it's still a prototype), It will enumerate as a joystick/keyboard and serial port on a pc (all standard hid drivers so works just as well under windows/linux).
If you don't want to create your own firmware (arduino (tm)) for it, then you can still develop something on the pc side. The serial port will stream x,y,z, gesture and touch data so it's easy enough to create a python, c#, program/script to use it.
We are also planning a bluetooth version with battery for a portable wireless device.
At the moment we are furiously creating more demos, code examples and documentation for it and would like to do a crowdfunding campaign.
I would like to get feedback on whether such an device is something practical and suggestions on how it can be improved 
web: www.umotio.co.za
fb: uMotio