This is such a great idea. It's called Contrail, and it deposits a path of colored chalk as you ride. I think this would be great for creating paths your friends could follow to find you, or as part of a scavenger hunt (especially a romantic one!).
In terms of practical applications, the Contrail will also help with bike safety, as "pver time these trails on the road get more pronounced, which not only encourages other bikers to take the same route, but it also lets drivers know what roads are frequented with bike traffic, hopefully making them a bit more cautious."
For more information, click
here!
I came across these postage stamps on David Leibovitz's blog. They look just like an unwrapped bar of chocolate, and they even smell just like the candy bar! However, they're actually just scented stamps.
