I like taking Melem (http://www.melemusa.com/) with me.

Main ingredient is petroleum jelly, and also contains liquid paraffin, lanolin, steric acid and 'perfume'.

You can get very small containers of it, excellent as a fire starter, and useful for many things such as:
-abrasions
-acne
-blisters
-burns
-chapped lips
-mosquito bites
-poison ivy
-sunburns
-insect bites
-cold sores
-calluses
-psoriasis
-jelly fish stings
-sea itch (it works wonders for this... trust me)
-diaper rash
-nursing
-etc