The ability to start a fire can mean the difference between life or death, but even in the best of scenarios, it will mean the difference between relative comfort or absolute misery. Of all the elements needed to start a fire, tinder is the most critical because it allows you to make up for poor fuel, kindling, and ignition sources.
Tinder, believe it or not can be found everywhere. You just have to know where to look. I found a great article that shows you 35 easy to find sources of tinder.