How Do You Take a Taxi with an Infant?

Stick out arm, wait for cab to stop, enter cab with baby, tell driver where you would like to go, hope for the best.

Belt them in like you would in any car if you didn't have the base. I assume all seats can be installed without a base -- I know the Gracos can. If properly installed, it's as safe with or without the base (the base is just handy because that you don't have to strap them in every time). Your owner's manual should have instructions.

Not being in the city, I am not sure, but I think you can use the seat of the
Snap and Go set.

I am going to assume you do have a car seat because you have an infant!

All car seats have an alternate installation without the base. You just basically use the seatbelt and there are these holes the seatbelt goes through. For the person who suggested you go without one... it is against the law and the driver can loose his job. Also they made it a law for a reason. IT IS NOT SAFE.
I have taken a taxi with my daughter dozens of times. Make sure you get it a little earlier than you need because it takes a few mins to get the seatbelt correct. I think you can probably look up instructions for installation on the website of your car seat manufacturer.

Great question! What about a bigger infant who is no longer in a "carry carseat?"

All the answers so far seem to assume that you own a car-seat.
It occurs to me that you do not.

This may seem unbelievable to many people here . . .
but in ancient times, back in the middle of the last century, for example,
we carried babies in our arms and did not have car seats.
Oh the horror!

Anyway, if you specifically request a taxi driver who is cautious
and not a hot-rodder, it seems to me you can sit in the back seat
and hold your baby in your arms.

Maybe bring a few pillows from home
to put between you and the front seat.

S.

You strap them in like you would in your own car. You have to bring the base of the car seat with you, or buy a car seat that does not require one. I reccomend that if you will be doing this often to invest in the type of stroller that the carseat will fit directly onto, to help for when you get out, to wherever you are going to not have to carry the baby around in the car seat all day.

I take her snap and go stroller and car seat. Put the car seat in the taxi (without the base) and put the stroller in the trunk.