Yup, I forget exactly what age, but DS gave up his nap early. His nursery used to send him to an older group of children who were having "quiet time" then, and I started to do the same at home - designate an hour when he had to play quietly in his room, but need not sleep. Worked well for him, and was extremely helpful to me, though I know not all children will cooperate! It helped that he was starting to enjoy reading independently around the same time. We did similar at bedtime: allowed him to read/play quietly if he didn't want to go to sleep immediately.
