Here's some gadgets that are nice to have:

1. Laptop. Yes, bring one. They're great for watching movies on and you may have the opportunity to use it for email, webcam, computer games, etc.

2. MP3 Player. If you like music. Something tiny that runs on AA batteries would be my first choice (vs. a larger iPod or what-have-you). I have an IRiver.

3. GPS. The Garmin Rino 120 is a decent one, but any will do as long as it has MGRS capability. Small is good; long battery life is good. More important for squad leaders and above than enlisted soldiers. Military GPS's are available but are big and bulky.

4. Thumb drive / memory stick. USB memory sticks are the primary way people move data around out here. Get one and keep it on your keychain or dogtags. Again more important for leadership than junior soldiers.

5. Digital camera - small is good; expect it to get dirty and banged up if you carry it with you (e.g. don't expect it to come home in new condition).

6. FRS Radio and charger. Something like the Motorola Talkabout. A set of 2 with 2 chargers would probably be ideal so you could share one with a buddy as needed. This too is more important for leadership than junior enlisted soldiers.

Since power is often unavailable, when possible either ensure that your gadget has a very long battery life with its rechargeable batteries or get something that runs on AA batteries, which are easy to come by.