Right to Bear Arms
Be very afraid link to the Something Awful forum where Roland Tower has made a flame thrower from everyday parts available from a B&Q. The only thing stopping being as good as military one is that it uses too light a fuel and does not have a heavier sticky base (though a quick trip to the kitchen or returning to B&Q would do the trick).
About five minutes thinking about alternative materials and you have a dummy's guide to hardcore weaponry.