Can you fix a tube with a lighter? I was thinking about a patching tiny puncture I got from a metal sliver in the road.  I usually don't even attempt to patch tubes, I always carry a spare, put that on and recycle the tube and forget about it. 

I was wondering if it would be feasible to fix a small hole in the tube by applying heat from a lighter until some of the material melted and fused back together.  Or even dripping some molten plastic or rubber over the whole if it were larger.  

Has anyone ever done this successfully? I'm curious about butyl and latex tubes.
No, that won't work because first and foremost tube rubber isn't going to liquefy and re-solidify and be fine; it's going to burn and be weak.

Traditional vulcanizing patches do more or less what you're talking about. The vulcanizing fluid acts on the rubber to permanently fuse the patch and make the tube as good as new. It's easy and gives predictable results.