Well all of the laser tag systems I've seen you have to where a vest with sensors on it that detect the enemy lasers. Which really sucks when you shoot someone but miss the sensor or say you go for a head shot and nothing happens.
I have a pair, as do 3 of my friends. We play games on a weekly basis. It's a hell of a lot of fun, surprisingly intense exercise, and the hardware works really well (I can shoot upwards of 150 feet away).