On the note of the laser puck:
From wikipedia(the source of all knowledge):
To create the FoxTrax puck, a standard NHL puck was cut in half, and a tiny
circuit board with a
battery was placed inside. The circuit board contained motion detectors and
infrared emitters that were located on the flat surfaces and sides of the puck. These additional enhancements added less than one-hundredth of a
gram to the original puck's mass. The two halves were sealed with
epoxy and the puck could be used for gameplay. However, the battery only had a 10 minute lifespan, so at least 50 FoxTrax pucks were produced before each game. The puck was activated when it was struck by a
hockey stick.
During a Fox NHL broadcast, the puck emitted infrared pulses to
motion sensors located along the boards of the rink. These sensors were synchronized to the pulses. Next,
infrared cameras along the rafters detected these pulses and transmitted their coordinates to a television van (also called the
Puck Truck). The truck contained computers that superimposed
computer graphics on the puck coordinates, which could be seen by viewers at home.
The visual result was a bluish glow around the puck. Unfortunately, blue does not show up very well against the white of the rink. Passes were indicated with the bluish glow plus a comet tail indicating its path. When the puck moved faster than 70
miles per hour, there would be a red
comet tail following the path of the puck.
Since the process could prove expensive, FOX employees would sometimes go into the stands to retrieve a puck that left the playing area, rather than let the fans keep the puck as they normally would during the course of a game.
