Okay, not technically a real lightsaber, just a very clever flamethrower of sorts. But don't diss it unless you can do better. Seriously though, don't: it's preposterously dangerous:
It's the creation of Sufficiently Advanced, otherwise known as Allen who you might have seen waving around a magnetic, thumb-locked version of Thor's hammer a few weeks back. This uses a fuel mixture of methanol and acetone, projected by butane propellent and lit by a red hot nichrome wire. Yes, it does sound incredibly dangerous, hence the don't even think about it warning.
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