Changed some default values. Modified Gravitational potential to avoid high force and low time resolution problems. Added Lennard-Jones potential. Default values for this need to be worked on as they're much more sensitive and likely to cause unstable configurations than the gravitational case. Rejiggered the hell out of the canvas drawing function, attaching values common across runs to the canvas element using the jQuery data method, added motion blur to particles. Played about with motion blur a lot to get some nice output.