Walk the Plank!
A pirate party surely isn't complete without a traditional walking of the plank. You can set this up in the backyard or in a room with carpeting. Get a long piece of wood (a 2-by-4) and some smaller blocks to put under each end. The blocks only need be a couple of inches high -- you don't want anyone to get hurt. Nail the blocks to each end of the plank and one in the middle for stability.