It is really going to depend on where he is stationed. There is no happy medium anywhere here. The camps are either so well stocked that it almost feels like home, or you can barely get enough water to get through the day.
An exageration of course, but you get the idea.
Many MWRs have boxes of care packages with stuff in them; toiletries, snacks, body care products, playing cards, etc. The BX/PX usually has most of what is needed on a decent base, but that of course costs money (one thing that is always welcome!). However, there are plenty of FOBs that haven't didely squat. So, find out what kind of place he's going to be in and make a decision. Otherwise it's a crap shoot as to what he'll use and what he'll toss into the box at the MWR..if there is an MWR!
Food is good. Beef jerky, drink mixes, home-made cookies area a hit. Video games, if he's into that. Many camps have libraries that you can get paperbacks, and the Iraqi shops get movies for about $3-4 before they even get to the states, so don't bother with those.
If he'll be outside the wire, is he using an M9? How about quality magazine rebuild kits? Mags themselves are a no-no, but springs and sandpaper are great. Same could be said for the M-16/M-4 mags. Basic repair and cleaning kits. Quality knife sharpener and a quality knife.
It's going to be cold soon, and I mean COLD. SOCKS (military style, thick ones)! Good quality shooter's gloves. Boot insoles.
Do not forget him on Christmas/birthday. There is nothing like getting a letter or package from home. Keep in mind that you will want to mail a little early. I'm already starting to see the Christmas rush come in, believe it or not. How about an iPod, if he has a laptop with him? New 80gigers are down to $250, for Christ's sake! Wait a month and buy 'em refurbed strait from Apple.
To bad you can't send him a deep fried Turkey for thanksgiving!
Tell him I said God Bless, and that goes for you too for taking care of him.
Fred