My 5 year old grandson comes to my daycare on his PD days and other holidays and my rules for naptime/quiet time are that everyone lays quietly in the dark for the entire time until everyone awakens. I only have two rooms for daycare/playing/sleeping/you name it! My living room/dining room. Anyway, I let my grandson bring his DS game to play and he quietly plays it for maybe 45 minutes then lays it down because it makes him tired and he sleeps for the next hour or so. Hope that helps for an idea or two for you.