Change - and Apple isn't perfect either

Why is change so odious? Here I was, humming along and suddenly, wham! my skin erupted. So, three months later, I am almost recovered and humming along again when, wham! my iPhone de-activated itself. Well, the second time my humming along was not so innocent: having successfully exported my address book from the old Windows 2000 PC and imported into the MacBook and then synched it with the iPhone, I was feeling pretty cocky. And also impressed with the amount of nothing I had to do on the Mac side. But flush with success, I proceeded to click OK on the Mac to a message informing me that there was an upgrade to my iPhone's software and did I want to install it? BIG MISTAKE. In true Mac form, I had nothing to do but sit and wait while the whole software upgrade took place before my eyes and then, suddenly, the iPhone changed into an iPod...the phone bit stopped working and announced that it needed to be re-activated. The only problem with that is, it needs be re-activated using my AT&T account, which is over yonder across the Atlantic Ocean about 5,000 miles away. Well why would I worry about not having a phone that uses AT&T when I'm in Israel using a completely different cellphone provider on a different phone device? Because 1) Now the newly-imported and synched address book on the iPhone doesn't work, and 2) When I land in the US the iPhone won't work there as a phone either because it first has to be plugged into iTunes to be activated. I think. If anyone knows differently, please tell me. I do so not want to drag my MacBook along just to re-activate my phone.