Two of the only genuinely living forms of folklore, constantly having new examples added on a daily [indeed, hourly or even minutely] basis, the joke and the "urban myth", are indisputably forms of folktale — appearing world- or nationwide, none knows whence, and being passed on orally at lightning speed.

Look at any of the 'joke' threads on these forums, read the books by Jan Brunvaand, Rodney Dale, et al; or go to a pub or a party and see how long it is before someone says "here's one you won't have heard before", or "you should just hear what happened to a friend of a friend's auntie", and begins an anecdote you heard earlier in the day from someone else who began with exactly the same formula, and you will see what I mean.

~Michael~