One of the most fun themed parties we have done was a water play theme. I wish I had pictures, but it was years ago -- before digital cameras! The kids all wore swimsuits. They played with water balloons, of course, and played with water guns, and played in the sprinkler. The best game was water baseball. We took a bunch of giant sponges and placed them in a cooler filled with ice water. My hubby 'pitched' the wet sponges to the kids. He made sure they got good and wet -- which was the most fun for the kids. We did self-decorated cupcakes for a snack and blue koolaid for drinks. It was a blast!