well, i'm not sure about an arduino but a positioning system for American Football so we can know if the rb got the touchdown or first down.
Strictly arduino based: Magic eight ball for the refs so they can figure out if that was a catch or not. Seems like they've needed some sort of help as of late.
I presume the purpose of the "hole popper" is to bounce the ball back out of the hole so the guy has to take at least one more stroke? Sounds like a great idea.
How about moving goal-posts for football? They have been the scourge of politics for years.
Actually, seeing as it is meant to be an Arduino-related project, I think virtual goalposts would be even better.
You touch the ball down and then consult the Arduino to find out if the touch-down was anywhere near where the virtual goal posts were at that moment.
Another option is a performance drug concentration detector - the one who crosses the line with the highest concentration wins. Much easier to enforce than a no-performance-drugs regime.
Robin2:
Another option is a performance drug concentration detector - the one who crosses the line with the highest concentration wins. Much easier to enforce than a no-performance-drugs regime.