I just got back home after a year in Iraq (as a weenie civilian lawyer). My two cents: handi-wipes, decent reading material (i.e., not Clancy-esque crap -- there's plenty of those novels at every FOB), headphones, brand name gum and candy, drugstore.com gift certificates . . .
To all of you who have someone serving, or have served, I thank you all from the bottom of my heart.
I'm sappy sounding, but it's true.