According to the old nursery rhyme, sticks and stones will break your bones. While I can't make any serious claims about rocks, I can say with some authority that one of the most overlooked items in a zombie kit is a stick.
Now don't get stupid on me and start telling that I'm crazy thinking a little branch will be effective against zombies. I'm not talking about that kind of stick.
When I say stick, I'm talking more along the lines of a staff or walking stick. Something about four to five feet in length and made out of some kind of hardwood. It doesn't have to be fancy, just functional. Before the fecal matter hit the rotating air mover, there was a company that made serious walking sticks. These things were made out of aircraft aluminum, had a compass on the top, and the end unscrewed to reveal a nasty six inch blade. One of those bad boys would be handy in the new world, let me tell you.
Anyhow, if have a functional, serviceable stick, you'll find it is a very useful item when dealing with the undead.
For example, you can use the stick to safely push the Z down, to be terminated in a more permanent fashion. Or you can use the stick to lever the ghoul out of the way or over a guard rail. You can throw the stick at their legs to trip them up, or you can shove the end in their mouths, rendering them impotent while you figure out what to do with them.
Duncan travels with an oak staff, and he likes to trip them up with it before he kills them. If he's with Tommy, Duncan will trip up a zombie, then hold it down while Tommy kills it. It's a pretty effective method.
Bottom line, a stick like what I'm talking about will have a lot of uses, so don't count them out until you try them.