These little things can be entirely too difficult to find outside of the US, but here in Canada I've found a handful of novelty candy stores who stock them, albeit at a staggering mark up ($1.69 Canadian a roll, last check). They can be worth it tho', if you get the right combination of flavours, a thing which hasn't seem to be properly mentioned on here. They are, and always have been:
purple: clove
pink: wintergreen
white: cinnamon
green: lime
orange: orange
yellow: lemon
brown: chocolate
black: licorice

I have to agree that the chocolate ones are the best, but they're all good. Except the black ones. Even the clove one, which has raised a few eyebrows, I don't mind.

Also, apparently, in dry weather and in the dark, when you snap a wintergreen one in half it makes a spark. Yet to see this happen, but even, where the above flavours came from, verifies it.