frankytalia - you are the man! Thanks so much for the reply and for the info.
I had been looking at TIM's site:
http://www.tim.it/
trying to find what the cost per minute would be - and I'm not doing too well....
Can I trouble you again? Do you know what the rates would be on TIM?
This is my situation - I come to Roma three times a year

and want to use the prepaid SIM card just to call my roman friends when I'm in town - so I've been trying to figure out which company would give me the best local rates. The other thing is, two of my friends have Vodaphone - so am I right in thinking that if I got a Vodaphone prepaid SIM card that it would have a better deal when I call them?