This right here is an incredibly faithful replica of the plasma cutter weapon from the excellent video game Dead Space. And it is awesome.
Created by Epic Weapons, there are two versions: one from the first game and one from the upcoming sequel. They both look great. They also apparently actually zap electricity, as they come with a rechargeable battery that keeps 'em juiced for a half-hour of full usage. Not that I expect them to actually fire lines of plasma that could take your arm off, but hey, you never know.