I used to tell this joke
But extended to an absurd length. I think my best telling (when heavily stoned, obviously,) was upwards of three quarters of an hour. It's all about building a richly detailed world, spinning a long and winding tale, and getting your audience properly invested in the story before finally slapping them with a really shit punchline.

Seemed funny at the time.
( Zoroastermouse thinks therefore he am, Fri 25 May 2012, 2:07, Reply)