Did a search, and this is a website that I found..
http://www.equipped.com/deployed_military_suggestions.htm
Baby Wipes - great for taking a field bath - packets are better than tubs
Beef Jerky/Slim Jims
Energy Bars (Power Bar, etc.)
Hot Sauce (Tabasco, Red Devil, etc.) - wrap glass bottle in duct tape and place in doubled zip-lock bags
Sunflower seeds
Peanuts
Seasoning Salt (Lawry's, etc.)
Atomic Fireballs / Jolly Rancher hard candy
Powdered Energy/Electrolyte Replacement Drink Mix (Gatorade, etc.)
Chewing Gum
Avon Skin So Soft - great for removing face paint and also reputed to be an effective bug repellant (the latter seems variable based on personal experience and reports)
AA-cell Alkaline Batteries
Personal Hygiene Gear: Disposable Razors, Toothbrush and Tooth Paste
Eye Wash / Drops (Visine, etc.) for flushing dust and sand out of the eyes
Zip-Lock style Plastic Storage Bags - assorted sizes, heavier freezer style are better
Copenhagen Snuff in a tin ("Even if the service member doesn't dip snuff, they will be a hero and have more power than the Commanding Officer if they have a 'log' (10 cans) of 'Hagen.' A large percentage of infantry use this stuff and it is hard to get. The stuff they do get comes in a plastic can and tastes terrible. The 'Stateside Hagen' is the most powerful bargaining tool in a field environment!")
Pre-paid Phone Card so service member can call home