Binocular Scavenger Hunt
Make a list of outdoor things you can see from various windows, using—surprise— binoculars. Be sure to vary the items from the teeny-tiny (say, a broken but beautiful bit of green glass) to the exceptionally large (say, an oak tree in the shape of a jolly giant), as well as from the very far to the very near. The first child who checks off every item on the list as "spotted" gets a prize. Our favorite reward: freedom from sharing toys for 15 minutes.