Andy posted this over on this section of the orange blog a while back
Now I have been messing with particles a great deal the last few days, but for the life of me, I cannot get each strand of hair to have that random waviness llike this example. He even provides the Blend file on that page and I have downloaded and studied it, but I cannot figure out exactly how the random curliness works. I believe it has something to do with the cloud texture in the 8th texture channel, as there is a reference in the particle settings to the 8th texture channel, but I haven’t been able to replicate these results (or get that texture channel to do anything for that matter) in any of my own tests. Is there someone out there who can help me, besides perhaps, Andy himself (I’m guessing he’s rather busy finishing coding Blender 2.4, and more power to him.)?