Following some advice from Ziner's we purchased an inexpensive cellphone from Mobal Rental http://tinyurl.com/aycwg for our trip to Scotland and England last year. We were very happy with the service and cost.

This year in anticapation of a trip to Canada we purchased a Pre-paid SIM card for my current Nokia phone as the other phone does not work in North America.

Another company with options is Telestial http://www.telestial.com/

As we have become a cellphone carrying world, having the phone nearby seems to make for more convience and save the need to navigate unfamiliar phone systems.

Good luck and enjoy your trip, Vince & Gerry in Philadelphia