Pretty much EVERY effect in The Paper Engine, lol.
Seriously though, there are about two in there that don't use it, and all the others that do are good uses for it. Some could even be considered entire exercises in using the half pass. One effect has two handlings, one uses 12 half passes, the other 8, lol. Actually, I don't remember the exact number of half passes in it, but there are quite a few used in just the one routine. It's, IMO, something just for fun and practice.