I went to italy last summer 8/2007. I bought a tim sim a few months before the trip and recharged it a couple times at any local tabac store.
It was not a lot of money and I was able to give my friends and family my italian number before I left,
I used https://www.telestial.com/ and found them to be professional and reasonable.
They (and others) offer a 800 callback number that you can purvhase service from if you plan on making a lot of phone calls out of country.

I was using a N95 at tge time and I bought wayfinder software to use with the n95's gps.. When I went to italy I bought a 1 month subscription to italian maps from wayfinder for a few extra bucks.
I do not know about telnav