I love Tea Tree Oil. It has some great anti-bacterial properties and it seems to speed healing. I used to use it on my face in high school to fight acne break outs. I definatly recommend it being in the backpacking kit for minor first aid.
When there was a lice outbreak in my daughter's kindergarten class last year, I started washing her hair with tea tree oil shampoo. Not sure if it was the oil, but she dodged the lice - whew!! - so I'd definitely do it again!
I love Tea Tree oil. I used a bottle to fight acne when I was in high school. It really works and tones the skin amazingly well. I wonder what my friends thought about the smell! LOL No one ever complained though!