These are awesome little devices for modern settings. Since the magnesium can be readily used for more then just lighting campfires (flares, fireworks, as a chemical, etc) these are truely cool. Go to Comment
Well, these things are far too useful to leave at home.
This + Steel Wool = Firestarted.
This + matches,electrical tape and a little copper wire, primative detonator.
This + Graphite lead from click-pencil = Temporary Carbon Arc Lamp.
Can be taken apart to obtain 6 1.5 volt (sorta) short-life batteries, allowing you to generate anything from 1.5 v to 9 in 1.5 volt increments.
Two stuck together = dangerous handwarmer.
This + two electrodes and water = hydrogen/oxygen generator (in small quantities).
etc,etc. Go to Comment