Something I find useful, is that most modern phones use a lead that plugs into the phone with an rj45 jack, and then has the local country plug on the other end.
I've been able to use this many times when I haven't had the appropriate local adaptor by just unplugging the lead from the phone and into the back of my powerbook.
If you're staying in a major hotel, most of them have phones that have an rj45 socket in the side of them for modem connections.
Enjoy your trip,
J.