I always had cats (and dogs) as a kid and don't remember ever finding hairballs. I don't even recall my cats ever trying to cough one up. I remember reading about cat hairballs and asking my teacher about it because my cats never had those behaviors.
As an adult, I've seen many cats trying to cough-up hairballs, but I still don't think I've ever seen one coughed-up. It would probably be super-easy to pick up, though. Nothing like the kinds of things a dog leaves behind.
http://webpages.charter.net/ichinisan/images/dog_shit.jpg
Oh. I probably shouldn't have embedded that. :sneaky:
[edit]
Decided to remove embedded image anyway...