Make rigid body collide with hair particles I have a ground plane set up with a hair particle system, it is set as a passive rigid body.
Now I want to be able to drop my Active rigid bodies, and have them collide and lay on top of the hair.

Further more I'm trying to find a way to make the hair particles mat down where the rigid bodies hit them.
As gandalf3 said, you can enable Collision on the rigid bodies, and set Hair Dynamics in the hair particle setting. (demo file) 

You can also add Force Field to the Active rigid bodies to simulate the collision, since Hair particles react directly to force fields: