There are alternatives to the normal mouse, e.g. the gyro mouse (cheap, but blocks one hand), the roller mouse / bar mouse (very expensive, but comes very close to what I want) or the trackball (very close to what I want, but way too hard to control the cursor because of the limited movement range / sensibility).
The objective of this project is to develop a headset, which may include microphone and earphone and a sensor to read the orientation (e.g. gyroscope, or gyro + accelerometer + magnetometer). The coursor should be controlled by moving the head up/down and left/right. There are different approaches to realize the click buttons etc..
The advantages of this HMI are exact positioning (because of huge movement angles compared to e.g. the size of a mousepad) AND fast movement (because of no keyboard-to-mouse-switching-time). In addition, this device can be used by people that are not able to use their hands to control the cursor.
you can use a wiimote+ as your headset. How to readout the wiimote you can find on the web-