I made a simple 2D special relativity simulator (sandbox?) as a final project for MIT 8.20, a one month special relativity class in January. You fly around in a spaceship, experiencing the distortion of space and time. Doppler shift is also implemented so you can see how the stars fade out of visible spectrum if you go fast enough. There is a clock in the rest frame so you can see the difference in time passing. You can play with it here (but I make no claim as to the physics being 100% correct).
