The function of zebra stripes

I just returned from South Africa, where the rangers were emphatic that the stripes are for camouflage. Not in the way we initially think when we hear camouflage either (to make them invisible), but to make it difficult for a predator to see how many zebras are in a group, and which way they're standing. Zebras can kick very hard, apparently, hard enough to easily kill a man, and if you don't know how many there are and which way they're facing, it makes sneaking up on a group risky.

Open still is the question of why zebras have such short hair...Apparently this whole hypothesis is predicated on the fact biting flies are a problem unique to Zebras because their hair is shorter than the biting implements of the flies.

I always thought the explanation I heard as a kid ("The stripes help them blend in to the tall grass of the savannah") was a bit lacking - this makes much more sense!

I thought was something like a "Dazzle camouflage" -http://en.wikipedia.org/wiki/Dazzle_camouflage

The principle it that would be harder to a lion know where they are heading when running. Actually the zebra is supposed to have inspired the development of this technique.

The explanation I heard as a kid was that the stripes confused predators. When they stand in a group the stripes allegedly make it hard for predators to attack from the rear.