What can steer a parent toward insanity faster than the phrase Are we there yet? ...the words Knock, Knock , of course. Bob Phillips, comic genius, has mastered a gathering of knock, knock jokes that will have kids laughing hysterically - and parents just plain hysterical - but a family that knock, knocks together, grows together. Knock, Knock Who's There? Olive. Olive who? Olive to tell knock-knock jokes. Hours of entertainment in one simple resource is the best deal in town.