I don't know about the Camino, but I used my iPhone in Italy and I had a very unhappy surprise when I got home and got my bill.
I was in Italy on work and I had to check and revise contracts quite a bit while I was there. What I found was that downloading 3 page contracts to my iPhone cost me somewhere around $40 each. For my two weeks in Italy between minimally using the phone (I think I made somewhere around eight 15min phone calls and one 40 minute call), plus checking my emails, using apps, and downloading contracts I got a bill for over $1500. Your best bet would be to use the WiFi next works with your own system i.e., iPhone, iPad, computer. This was in 2007, and the plans have changed quite a bit, but be aware how much a KB is and how many of them that you are using for the most basic things.
For trips now I have a international phone, and I purchase a new sim card for the country I'm in. I then leave the new phone number as a message on my old phone. Also, I set up a new email for my trips, so that I'm not getting a bunch of spam to the new phone.
I travel quite a bit for work, so these new emails are great for giving out to the people that I meet on each trip. This way I have a better idea of where I met them, and at the end of the trip I just have that email forwarded to my main email address.