This fantastic project is good for fun, survival, or even just a project!
MATERIALS: small flashlight, pliers, flammable material (ie gasoline or bug spray soaked cloth or pine straw), electrical tape, and scissors.
and Preferably a flashlight with minimal cracks, holes, open spaces, etc.

Step 1: Disassembly

Disassemble your pocket sized flashlight and pull your bulb and stuff connected to your bulb out of its case.

Step 2: Break Your Bulb!

I know this sounds crazy and incredibly stupid, but the fire starts when the filament gets hot enough. the filament has to be right next to the flammable material. with the bulb in the way, the material can't get hot enough to burn. so CAREFULLY get pliers, a rock, or something and break the bulb. But if you break the filament you have to get a new flashlight. you will probably want to break the bulb over the trash or something. BE CAREFUL WITH THE FILAMENT! That means don't drop, throw, toss, touch, breathe on, or let the filament touch anything! IT WILL BREAK.

Step 3: FIRE

Find/make your flammable material. you can use pine-straw, dead grass, 100% cotton rag, 100% cotton rag soaked with bug spray, 100% cotton rag soaked with gasoline, or 100% cotton rag soaked with something else flammable. Remember, you don't need a lot of pine straw or cloth or whatever, and plus you need it to fit in your flashlight, which needs to fit in your pocket!
When you're ready to light, put the flammable material next to the filament. Turn on the light. Hopefully after a while the material gets hot and lights. I won't tell you how to make a fire because that's an instructable on its own!

Step 4: Waterproofing

to water proof, you need electrical tape and scissors. you will also need to put the material you will burn COMPLETELY in the flashlight case. next, use the electrical tape to tightly wrap around ALL holes, crevices, cracks, holes, etc. tightly.
IN ACTUALITY, YOU'RE DONE.