"Hair" was, I think, an abortive attempt to do what the Hair Room in P5 does now -- it actually can be used in P4 in tandem with the grouping tool; I think there's a tute on it around here somewhere. Btu it can also be used to make trees, grass, what have you, by applying it (gaain, probably using the grouping tool) and letting it do its thing. Not terribly realistic and a major resource hog, but there you are.