http://www.youtube.com/watch?v=qaPuPouEfbM

Browsing on youtube, I found a game named after the two German mathematicians Carl Runge and Martin Kutta.  The author of the game says he used the Runge Kutta method to simulate the spring in the game.

He says he uses RK4 with a frame timestep of t = t + 0.1, when running at 60fps.  He says he used the Runge Kutta method because RK4 appeared accurate and fast compared to the other methods out there.

By clicking on the link, you will see a quick demo to the game.