lightbulbs are not a load of shit, they work just like any other device used to freebase a substance. The real problem is the material that goes into making bulbs may/may not be toxic in high heat situtation so if you give a fuck you'll find something better (e.g. testtubes, petri dishes, glass cigar tubes...)
I'm not to sure on how much thc is lost due to excessive heat exposure but it most certainly gets me baked on a lot less pot. Its not hard, just dont let the shit burn and if it does, so what! You're still get high with no butane. But if you want something that you can smoke out of w/company then a real vaporizer is the only way to go.
thats what i use:
http://boards.cannabis.com/attachmen...0&d=1154894392