I recommend always carrying a roll of rescue tape. It can seal oil lines, gas lines, radiator hoses, all while leaking. It can also (but I've not used it for this)be used in an emergency to cover a wound, like a cut finger. It's really some pretty awesome stuff, I've used it for a couple years.
http://www.rescuetape.com/
Between this stuff, JB Weld and Zip Ties, there is really nothing that can you can't temp repair.