From GameWatcher: "Aperture Hand Lab is, technically speaking, a video game. This interesting piece of software puts you into the control of a pair of precision-tuned sensor-rich re-imaginings of your very own hands, as they are presented in a high-fidelity simulated reality.
In practice, Aperture Hand Lab lets you take control over your hands in VR. In the Portal universe. Of course, this only works if you've actually got a VR headset and controllers, so your mileage may vary."