my 2 year old (almost 3, but has always been this way) can play alone for HOURS. he will get up at 5am and sneak downstairs and get into all kinds of things and i won't wake up until 8. not good for the housekeeping, but at least i got the sleep!

my 4 year old can hardly play alone AT ALL. if i am in the room with him, he can self entertain to a point. i think he may have ADD, though. that's another story...