Take a 2 liter soda bottle, poke holes in it. Attach to a garden hose. Toss over a tree branch and let hang for a kids water sprinkler. You can loop it over a tree branch and let kids bat it around for more watery fun!
Shell wind chime, a great diy project after a day of collecting shells at the beach! Each strand you do can have shells from different places you have travelled to. You can create small and longer strands depending on where they will hang.