Besides the basic "ouch, I have a small scrape" stuff, I carry sutures, a snake bite kit, sunscreen, stuff to survive a few days if I'm really screwed, road flares(they will start a fire in the shower) and a .2 micron water filter. I also carry 145 oz of water for most hikes/caches...man that is ALOT of stuff. I usually like to hit the hard terrain with my two dogs or for the easier stuff I bring my kids along, so I am always carrying for more than just what I need (my pack only weighs 20 lbs).
BTW I have never had to treat myself, it has always been someone else........hey I was a Boy Scout and I have no excuse for my preparedness.