Apple iPhone
iPhone Proprietary Sim Card maybe the dealbreaker
As a mobile phone enthusiast on AT&T I have been swapping my sim card between my collection of unlocked phones and enjoying having choices of what phone I want to use.
So If you want an iPhone you either give up the joy and flexibility of being able to buy whatever GSM phone you want, OR, you must buy another 2year contract along with your iPhone so now your wireless phone expenses are doubled.
http://www.nytimes.com/ref/business/20070627_POGUE_G ... »
But the phone might still be locked to your itunes account so that would still make the phone locked to apple and AT&T. In other words you might not be avaiable to take a US version of the phone Europe becuase you only have a US itunes account.
Either way, you have to activate it, and continue to pay the bills to be able to use it. If at any point your service is shut off, the phone becomes a paperweight.
If you want, you can take your SIM card out and put it in a regular phone (especially helpful if you have to send your phone to apple to be serviced).
So you can still swap your SIM among various phones... but only one SIM will work in your iPhone at any one time.