Last weekend we ended up traveling with the baby for almost two hours on public transportation. By and large, he was a good kid, but when we're out in public, we tend pull out all the stops as quickly as possible in order to keep him quiet and happy because the only thing worse than a screaming kid on the bus is knowing that he's your problem. While we did our little dance in order to keep him content, I realized that when you're in public with a kid, you do a lot more out-loud narrating and reassuring. Ostensibly, you're speaking to your child but what you're really doing is speaking out loud to all the people around you letting you know that you have a plan and things are going to be fine (and possibly, as a follow-up, that you are not a bad parent.) Here are some examples:

Scenario: Baby is noisily bored.
At-home version: Offer him some books. Take out some pots. Let him climb the stairs.
In public version: iPhone.

Scenario: Baby is noisily hungry.
At home: Put him in his high chair, let him whine and complain while you get his food together (food he may or may not eat) because he doesn't understand the concept of patience yet.
In public: Say in a high-pitched panicky voice, "Are you hungry? Don't worry! Food is coming! Food is coming!" while you rush to get snacks out as fast as humanly possible, offering him any possible thing he would happily and quietly eat.

Scenario: Baby is noisily tired.
At home: Get him ready for bed as he crankily protests you putting on the lotion he requires in order not to have lizard-skin and then you putting on his various pajama elements. Maybe offer him a pacifier and then just deal after he throws it on the floor and bitches some more.
In public:Say in a voice you hope sounds sympathetic, "Oh, you're sleepy. Poor sleepy guy."

Scenario: Baby has pooped himself.
At home: Change the diaper while merrily proclaiming "You stink!"
In public: Change the baby in grim-faced determination while lavishly praising the baby for not crawling away or throwing his feces like a monkey.