There are some good considerations here. I'm currently most interested in fire starters for when I go off piste snowboarding. The issue of temperature keeps raising it's ugly head, thanks for reminding me. Instead of a sparker device as part of my system, I'm inclined to carry an extra ferro rod. I started a new thread for this issue:

http://forums.equipped.org/ubbthreads.php?ubb=showflat&Number=209081#Post209081