A little public service announcement: don't let Rome cab drivers rip you off! There are fixed rates (with the official Taxi company of the city of Rome):

From Fiumicino to Rome center: 40 euros, baggage included, up to 4 people.

From Ciampino to Rome center: 30 euros,
baggage included, up to 4 people.

The drivers cannot refuse to take you, wherever you want to go in Rome. It is not uncommon for drivers to prey on tourists and ask 60 euros or more, or to refuse service. This is illegal. You can threaten to call the cab company by saying: "La tariffa ufficiale e' di trenta/quaranta euro, altrimenti la denuncio".

Thanks for the tip, Eric.

You're welcome.

Thank you Eric, I read someplace that the address you are going in Rome should be inside the walls...will the Trastevere, near Ponte Gharibaldi be included.
I also read that taxis should be the all white or all yellow, that is a City Rome taxi. Is there a line for them in Leonardo. We are flying from Milan. Tks

I meant to add that this is great news, before this news I was contemplating taking a train and then a taxi but the difference is not that much and the convenience is so much better than all the hazzle of the train, the luggage, and then a taxi.

Trastevere near Ponte Garibaldi is definitely within the walls. They should be Rome taxis, with a shield with "SPQR" on them, and they should have meters. And yes, there are taxi lines as you come out of the airport at Fiumicino.

P.S. That might have been ambiguous. They do not use the meters for the trip from the airport to the center, but "illegal" cabs without meters sometimes line up at Fiumicino as well.

I always write the address of my hotel on a piece of paper, show it to the driver and ask how much. But I also research how much the ride should be before I leave home.

Very interesting fact. But I think I'll stick with prebooking www.romeshuttlelimousine.com who will meet and pick us up at Fiumicino and deliver us to our place in the center for a total of 35 euro.

Always take a regulated cab. If you don't you can negotiate a fare up front. I stood in a very long taxi queue with my tired, cold parents and no taxis were coming. I saw some unregulated cab drivers parked near by and asked them the fare to P. Navonna and he told me, I agreed to it and off we went. We did this several times when no regulated cabs could be found.