In case you haven't noticed yet, Apple is now offering the unlocked iPhone 4S. They will only work on HSPA networks, no Sprint and Verizon's CDMA. But you can take it around the world and use a pre-paid microSIM card.
The prices are $649 for the 16GB model, $749 for the 32GB and $849 for the 64GB.
The unlocked iPhone includes all the features of iPhone but without a contract commitment. You can activate and use it on the supported GSM wireless network of your choice, such as AT&T in the United States.* The unlocked iPhone 4 or iPhone 4S will not work with CDMA-based carriers such as Verizon Wireless or Sprint.
If you don't want a multiyear service contract or if you prefer to use a local carrier when traveling abroad, the unlocked iPhone is the best choice. It arrives without a micro-SIM card, so you'll need an active micro-SIM card from any supported GSM carrier worldwide. To start using it, simply insert the micro-SIM card into the slot on your iPhone and turn it on by pressing and holding the On/Off button for a few seconds. Then follow the onscreen instructions to set up your iPhone.
Would you rather spend $649 and be free of contract obligations? Or would you rather be get it cheaper upfront and be tied to pay thousands of dollars over a two year period? [Apple]