On the Log Ride at Knott's Berry Farm they have infrared light beams above the log flume that trigger a loud pre-recorded "Sit down!" message if you raise your hands up too high.
It was so much fun in Jr High to try and set them all off.
Makes me think of the digital speed limit signs that start to flash red and blue when you hit 10 mph over the limit. Like of course every 16 year old kid ever is trying to make them flash red and blue and also me at 32.
In the UK, we have signs that show a happy face when you're under the limit and an angry face when you're over. It's hard to resist the temptation to go a little over to make it frown.
In Ireland, they used to show the actual value in flashing red when speeding, but getting the "highest score" became a goal amongst the youth, so now they just say "TOO FAST" when more than 10km/h over the limit.
When I was at TomTom, they ran a contest for employees to come up with fun ways to gamify their internet-connected GPS Personal Navigation Devices.
Some wise guy came up with the brilliant idea of maintaining a real-time "Top 10 Speeders" leaderboard for every single road on the entire map. Kinda like Foursquare for speeding on local roads. No matter where you were driving in the world, you could instantly see the top ten speeds of other TomTom users who drove down that same stretch of road, and put the pedal to the metal to claim or defend your own spot on the leaderboard!
That one went over like a lead balloon with the legal department.
The only thing worse would be a chat app for texting while driving above the speed limit with other Leaderboard members along the same stretch of road.
They also didn't appreciate my proposal for TomTomagotchi: a simulated personality on your PND that relentlessly begs you to drive it all around town to various interesting places it wants to visit, to improve its mood and satisfy its cravings. (Kind of like having virtual kids!) I'm sure there's a revenue model having drive through Burger Kings and car washes pay for placements.
It was so much fun in Jr High to try and set them all off.