How do I make hair collide with a mesh? I just downloaded the release candidate for blender 2.74 because it said on the release notes that it has  "Support for hair collision with meshes" and I would like to make it so that my hair particles stay inside of a hood that I modeled for my character. If anyone could give me insight on how exactly I can accomplish this effect it would be greatly appreciated.
You can't just turn on collision on the object and expect it to work.

Here is how u do it: first of all create your hair particle system.

Next turn on Hair Dynamics and turn on collision on the object.
Now go to the mesh with collision on and turn up the "soft body and cloth" outer and inner paramaters to say around 5 for both.

Now you can go back to the hair and turn up the steps to about 40 in the Dynamics tab. Now you should have good collision without the other nonsense. Also be careful when changing the other paramaters, it can slow everthing down tremendously.