My last two instructables where about computers, this one is very low tech
It explains how make a pen using wood, or actually, coal
It's easy, cheap and it's green!
Step 1: You'll Need
1: a thin stick (tip: used)
2: a lighter or matches
3: a (dry) pen
4: paper or if you really want to be green, bark from a cut down tree ready to be produced (it's usually burnt or thrown away, so it's even free)
Step 2: Preparing the Wood
Take the stick and light it.
Let it burn for a few seconds and blow it out. If a small piece keeps smuldering it's good, just let it for a few seconds and then remove air from it (just grab it between thumb and first finger if it's small, if it's larger use a piece of cloth)
Step 3: Making the Pen
break off the stick to about the size of the ink pattern in the pen (the exact length, plus the difference between the tip while not writing and writing), remove the pattern and (if it's in there) the spring.
Put in the stick and write away