Oh, I was under the impression that all residents in Italy had a codice fiscale.

Anyone can get one. Get your cousin to take you to the local tax office and you can have your own in 20 minutes. Or just use the generator online - it'll work fine.

But to go back to the OP, many/most services offering the chance to buy/rent a phone before you leave the US are a rip-off. A couple of years ago, a friend of mine came to Germany and rented a phone for "only" $69 a week (plus shipping and handling, and deposit for the phone). It contained a Vodafone CallYa prepaid card. At the time, you could buy a CallYa SIM plus phone at MediaMarkt for EUR 7.

A codice fiscale is just a way to determine some pieces of information about a person. It's composed by:
- 3 consonants from the surname
- 3 consonants from the first name
- the last two digits of the birth year
- a letter for the month (every month has its own)
- the two digits of the day of birth (+40 for women, to recognise the gender)
- a code made by a letter and three numbers, depending on the Comune of birth, every Comune has its own)
- a letter, not determined by something, but different, in order to recognise people with same name, and born in the same day and in the same Comune.

So, everyone could have one. :)

Thus, I can generate (for example, there Codice Fiscale .com - Calcolo del codice fiscale on line!) code, print, and when buying a contract to show it? Or do not work out?