Put a tarp out, put the sprinkler on top of it and presto, a large area for everyone to jump, run and splash around in. The water stayed on the tarp so it eventually became a slip n slide for them too. Add a few plastic balls... Won't create so much mud!!
Write notes back & forth with your child. Leave it on their bed, when they have a chance, they write back and leave it on your bed. How neat would it be to have those notes to look back on? LOVE this idea doing this!