Here we bring you a laser you can't use, followed by one you can.
First up a company called Wicked Lasers is producing and selling "The world's first and only LaserSaber," a $100 Jedi sidearm facsimile that's not quite ready for combat. Amusingly, the device's 32-inch-long, transparent polycarbonate "blade" fills up with laser light via gravity—you know, like those pens that you turn upside down to make a woman's dress slide off—and is apparently so bright that the user needs to wear darkened safety goggles. (The company sells those too.)
The manufacturer also notes that the device does not produce any sound effects and oughtn't be used for "any form of fencing or swordplay." Unlike the guys in the commercial:
I guess the real dealbreaker will be that you can't use the thing for actual contact. The no-sound-effects thing won't matter; most Star Wars geeks I know are entirely proficient at making those sound effects with their own mouths. Hand them a wrapping paper tube and you'll see.
Secondly is this must-see bit of laser awesomeness (source unknown, sadly). The action starts at 0:30: