One of the things that I noticed when I was in Iraq, was every time a group of new soldiers came in, at least half of them immediately went to the "Watania" shop on post, in an effort to aquire instant comms with the homefront.
Others, trying to be smart, "plan ahead" and buy a phone in the states, only to find that it doesn't work in Iraq. Or worse, they get sucked into a contract, which of course is completely useless. Most of the service personel that work for CDMA networks, don't even understand the most basic technology they're selling.
Here are a few things to remember when buying a phone with the intent to use overseas:

1. GSM= INTERNATIONAL (examples of American GSM networks are Cingular and T-Mobile USA)
CDMA = DOMESTIC ONLY!!!! (CDMA networks are those such as Sprint and Verizon)

Say what you want about either of these two technologies, the fact is, if you work (or play) internationally, GSM is the only way to go, hands down. No matter what any sales person tells you (either through ignorance or blatant deception), CDMA phones will not work outside of the United States (with the execption of Iraq, because we installed some towers there as part of reconstruction efforts- that being said, coverage is extremely limited, and GSM is still likely to give you the most value for your dollar).
How do tell the difference? Simple: if it has a SIM card, its a GSM phone. I'll say that again: IF IT HAS A SIM CARD, IT IS A GSM PHONE. If the sales rep can't produce a SIM card for you, then it isn't GSM and they are lying.

2. Know your frequency bands. American GSM operates on GSM 850/1900, while everyone else is on GSM 900/1800. For the layman, make sure the phone is "triband" or 'quadband". This is a little bit harder to discern without some research on individual phones. However, if you've already established that the phone is GSM, then you can possibly trust the sales person to steer you in the right direction.

3. Go prepaid. Mostlikely, you will just want to get an Iraqi (or Afghani, depending on your hotspot) SIM when you get there, or face some pretty obnoxious roaming charges. Now here's where it gets a little trickey. American GSM is locked down tighter than a prom date. Most of their phones are locked to a specific network; meaning that the 130 dollars you dropped on your shiny new RAZR will only accept SIM cards from the network it was purchased from.
Now, you can unlock most phones for a fee online, but it can be a pain in the ass, especially Motorola. So your best bet, is to do some research, find a phone you like, and then buy it online unlocked. Make sure to shop around; you shouldn't spend more than 300 dollars on an unlocked phone. it seems like a lot compared to what the networks are offering, but just remember; they are compensated in ways you can't see; like a contract or locking you in to their network. In general buying online offers a "no strings attached" option that I find more than appealling.

Well, that's it for now, stay safe and come home- you deserve it.