My traveling phone is an unlocked Nokia E66 with 2100mhz 3g that I use almost exclusively for travel. It has Jokuspot, Roamcall (a nice smartphone dialer which handles calling card dialing, callbacks, etc), Skype for Symbian, a hacked copy of the Three version of Skype for the Three network hacked to run on a generic Symbian phone, and Truphone.

While my other phone is a jailbroken iPhone on iPhone International unlimited worldwide data, I could use my Nokia to push a data signal to my iPhone if I was paying roaming or happened to be in a country or place where ATT did not have a roaming agreement. I could just as easily use that setup to push the data to a CDMA iPhone.