Just tried this on a small scale (3 x 5 ft) and it's already a ton of fun. Stick a small one in a shady spot on a hot day. The Water Blob tutorial: Amazing (and budget friendly) summer fun activity for all ages.
Play water volleyball Attach your hose to the Aqua Blast Volleyball set ($20; hearthsong.com)―it sprays streams of water straight up, creating a “net” for a wet volleyball game. Kids as young as 3 years old can play.