i was fooling around with some particle systems and i got a really cool “flock” effect.
the problem is, i have no idea what i did to make it do that! anyone willing to to have a look at the blend and shedding some light? 
thanks!
edit: i cant get the .blend file to upload. it says “file upload failed” what could cause that?
edit2: i just realized: the blend file is 6mb! i uploaded to drop.io
link: http://drop.io/vhqs69v#
You have a boids particle system, not the hair or newtonian. You can check out the wiki etc for boids (or pick up a copy of my book at Barnes and Noble - Foundation Blender Compositing) for more info.
For a cool ‘Geometry Wars’ flock effect, I quite like using newtonian physics on the particles.
Add a little drag and -z acceleration so the particles very slowly float down. Brownian motion helps too.
Add an empty and apply a ‘Spherical’ Field to it in the Physics panel. Make the strength a negative value (around -4) and give it a large MaxDist value (remember to click ‘use’). The MaxDist option will have a preview in the 3D window.
If you animate the empty around the particle emitter, you should see the particles flock in a very galaxy-like way.
I’ve been playing with this in realtime with blender 2.5. It’s awesome.
anyone? 
i dont normally like doing this…
bump
The Group you’re using for particle visualisation is a single plane, i.e. Plane.022 on Level 1. This plane has an offset to the center of the coordinate system. Combined with the slowly rotation of the particle system, this gives the “flock” effect. It’s a geometric effect, the particles are moving independently of each other.
HTH
SoylentGreen: the group is made up of a whole bunch of subsurfed planes. im not sure what you mean
In the file you have provided there is only one object in the group, i.e. Plane.022. All the other planes are not in the group. You can delete these objects without changing the particle effect.