water purification tabs (I put them in My FAK with other meds)
Swiss-tech makes several bladeless multi tools that will get through, security. They are Fairly inexpensive and often in costco, walmart, priceclub etc this time of year in multi packs.
I also pack a pair of EMT shears, these strike a ferro for niceley and can cut better than most knives, for many tasks.
+1 on Swisstech but not all of their gear is kosher with TSA. Please use common sense. I have been wanting to get a Wenger Air Traveler or Clipper AT as well.
BTW: I did once have my trauma shears confiscated. No, it didn't make sense to me either.