Locks and Keys provide hours of fine motor workout, spatial awareness and, well, just plain fun.
Get a variety of locks so that the children have to determine which keys work with which lock. We hide the locks before the children arrive or when they are not looking so that they discover them on their own. We also hide them around the playground. Problem solving, spatial awareness and fine motor skills are all targeted. This is an activity the children return to again and again, which supports my premise that the Hardware Store is the best "Teacher Supply" Store.