I want one or 2. I think it is a great idea for rides and trips. It would be a way to find my car after a pub crawl ride. Hansel and Gretel style. All I would have to remember is what color was on the wheels.
Or a ride that would be like "Fox and Hounds." One rider would leave early and make a trail to follow. Maybe a 15 minute head start. The rest would chase him. Certain bicycle groups would spray paint arrows on the roadways for others to follow at their leisure. Then give out clue sheets for the rides for future dates.
But, I would turn it off a mile from home so no one would find my stash of bicycles. Hehe.