Half-Rubber, a game commonly played at the beach, is a loose derivative of baseball. All the equipment that is needed to play is half of a hard rubber ball and a half-rubber bat. If an official bat is not available, a 48-inch section of a broom handle or mop will suffice.
References:
Half-Rubber – http://www.halfrubber.com/index.php?option=com_content&task=view&id=21&Itemid=31
Photo – http://dining.savannahnow.com/news/2007-07-13/whole-lot-fun-halves