[EDIT] This may belong in the Cargo Hold, but since I'm not selling them, I automatically put it here. Actually, I MEANT to put it in the Soft Parts section. Shows you how much I'm paying attention.
I bought two of these Balaclavas for Trooping. They're $8, and fit into an ammo pouch! Black, super thin like nylon stockings, and very breathable. You can see through it, but for under helmets....it's GREAT. No pasty chins showing under your bucket!
I also got the fleece ones from Cheaperthandirt, but they're for colder weather.