An interesting article, but IMO it is just there to give the phone companies more money.
For example, travel to China and I can use Rogers from Canada still. But the cost!!
It is far cheaper to unlock the phone and just get a China SIM card and go that way. If you need to call home, get a calling card. That completely removes the issues of carrier compatibility in the other countries.
Get a quad band GSM phone and you should be fine in most places.
If you travel with a laptop or a netbook and will have access to a high speed internet connection you can save some money by buying Skype credit. The credits never expire and the rates are much better than phone cards. They also sell unlimited monthly plans to a chosen country or all countries. You can simply buy 1 month of the unlimited to US and Canada for 2.00 USD I believe.
