Original work and code
So I stumbled on http://wonderfl.net/code/23f89f2a5e8d9df21c8a72210c2a22c9c7490600 some work at wonderfl.net some time ago and wanted to play with the code. Seems it is a ported to AS3 from Processing experiments. Works pretty fast but it does not behave as good as I would like...

Changes I made to the code
Here first version. Did not do much. Made it bigger, added my FPS counter, changed drawing methods, made some optimizations and made it show 20K of particles instead of 6kin original, made it repeating (left side connected to right, top to bottom, particles reappear on other side of the screen when they leave it). Also added "time to live" to particles so that when it expires they reappear in other random place. This way no space is left without particles for long (something I did not like in original version).

Planing to play with it more adding some effects, colors, objects you can drag to stage (particle emitters, walls, constant pressure or speed fields) etc etc. Will see how it goes :)

Controls
Just click and drag to create wind.
Double click to restart.

Update 1.1
Added colors and blur effect, become little bit more heavy on CPU. Fixed little bug with particles kind of teleporting when crossing screen border at high speed.