Thanks everyone for your replies. I have settled on a magnesium starter. Cabelas sells one made by Doan Machining and Equipment Company that is apparently indestructable. It is basically a block of magnesium, with a sparking rod attached. Use your knife to scrape some metal filings from one side, and then draw a spark from the other. That and a little securely packaged dry tinder, should suffice.

Wally world sells them too,in the camping section.