I did NOT want to Jailbreak any iPhone. I believe in R&D and do not want software through any back door. But Apple and AT&T left me no choice. It is required in order to unlock an iPhone for use by another provider – even when that phone is out of contract and in fact, the owners of the phone continue to be clients of both companies via newer phones.
By day two in Mexico I had had so many meeting complications due to lack of a phone that I headed over to an Internet place to Jailbreak my iPhone 3GS. (The process requires Internet access.) Jailbreaking was successful. However, my particular phone was not supported by the software available so i still had no option to make/receive calls.
Frustration continued.