As the Leonardo (and compatible boards such as our LeoStick) can easily emulate a mouse - and the Nunchuck can be read via USB - a mouse with some interesting physical movement requirements can be created.
To find out more and review the Arduino sketch, visit the project page. And for more, we're on twitter and Google+, so follow us for news and product updates as well.
To get started with your own embedded-Arduino and USB emulation projects - look no further than the Freetronics LeoStick. Apart from being one of the smallest Arduino-compatibles on the market with USB, it also has an onboard RGB LED and piezo for sound and knock detection: