Play around by moving your mouse! (for fun, you can play a game of seeing how well you can control moving the sand from one spot to another)
Went back to playing a little particles with some simple mathematics, and voila it create some interesting patterns.
Added some gravity/attraction interaction to it and it became kinda fun to play with.
(Has multi-touch support but awefuly slow on mobile devices! Wonder how it'd perform with a windows touch screen or a leap motion...)