Here's another handy tip to keep in mind if you're stranded on the side of the road and need to start a fire.  In this clip below, survival weblog SurvivalTek demonstrates how to start fires using a set of jumper cables hooked up to your car and a standard wooden and graphite pencil:

The trick is to start by first putting together your wood and tinder bundle and then cutting two notches in the side of a pencil to attach jumper cable clips to the graphite in the pencil. Then you'll just need to attach the other end of the jumper cables to your battery, start your car, and the pencil should soon catch fire.

While this probably is not the safest or most responsible way to start a fire, in a survival situation which involves using the need of fire for signal or warmth, then this trick might just save your life!