I used to make fun of the absurd Fox Puck, but a part of me thinks it would look cool if the hockey puck had LED lights embedded within. It would look remarkably different for starters, the Fox Puck relied on graphics applied in the TV broadcast (much like the line of scrimmage in football); whereas the lights would emit from the actual puck and be cast onto the nearby ice surface, boards, skates, hockey sticks, etc.
The puck would be more apparent in scrums in the corner and in the crease. I don’t know if it would look like a blur of light from a slap-shot, but I’d like to think there would be some tracer effect.
UPDATE: since I posted this 4 years ago I’ve received many inquiries for such a puck. A few products have come and gone, and there might even be a new one now, but there’s nothing I can personally recommend.