Seriously, are you REALLY surprised that pocket lint and bellybutton lint are not listed as a fire starting method? Just curious.
I was being sarcastic with the belly button comment, but not with the pocket lint. I have use lint as a fire starter in the past when in a pinch.
Another item I find starts a great fire is dryer lint. I will sometimes shove a handful of dryer lint in my pack to start a fire. It is excellent tender.
