My son is stationed in Iraq. The latest bunch of packages I sent to him included candy of various types, some word find type puzzle books, some batteries, some paperback books, a batch of computer gaming magazines, local newspaper, some pre-sweetened koolaid powder packets, a back massager (one of the ones from the dollar store), a couple of packs of playing cards, some miscellaneous CD's, some DVD's (most have access to someone with either a CD or DVD player somewhere), some pre-packaged cookies, cans of pringles, and some other stuff from the dollar store.
Things to avoid - candy that melts, baked goods without preservatives (figure 3 weeks in transit in hot/cold/dry/moist conditions. "Hey guys, the stuff in the package says brownies but they are more like greenies..." anything that you would not want to find in your 12 year old childs hands. ALCOHOL. Any tobacco products UNLESS you know who you are sending them to and they tell you its OK. Any magazines from the "top shelf" at the bookstore (even some of the ones like "Stuff" can be a little to over the top...) Anything that has LOTs of liquid in it.
Tips on packaging. Make sure you wrap it, bag it, pack it with the expectation that it will be thown onto a C130 and then OFF a Humvee and will probably BOUNCE in the process. Opps, forgot to mention the "no fragile or easily breakable" stuff either.
Hope this helps!
Proud parent of a son who he constantly reminds to keep his head down.