[halfnormalform]

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.

[frebord]

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.

[Veen]

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.

[sixstringtheory]

I especially like do that on my road bike!

[toast0]

If you do it enough, the attendant yells at you over the PA, as I recall.

Sadly, they got rid of the box car racers elsewhere :(