For my last game of Humans vs. Zombies I decided that I would utilize the least effective strategy possible. I optimized my weaponry for highest visibility, lowest mobility, and lowest zombie-killing ability.
So, naturally, I went to the shop, found some scrap wood, and threw together a back-mounted catapult, powered by twisted up bandanas of HvZ's past. When that proved to be a little bit too pathetic I added some rubber bands, increasing the range to about 30 feet. To defend myself from zombies I needed to either set the catapult on the ground, or get a nearby friend to be my gunner as I crouched down.
I did not tag any zombies with this, though not for lack of trying. My friend and I went hunting for them on my way to class - the zombie who tagged me didn't even realize I was playing until we started hooting and hollering and gently lobbing socks at him.