You might want to look at the Exotac nanoStriker. A bit expensive, but small and it works pretty well.

http://www.exotac.com/index.php?main_page=product_info&cPath=66&products_id=181

I wrap a piece of Rite in the Rain paper around the ferrocerium/magnesium rod for tinder and put a piece of Coghlan's Emergency Tinder in the striker compartment.