Jokes you've made up...

[JayzusB.Christ]

(Applause)

[Colin YNWA]

Came up with this a few years back, but I'm sure others have come up with similar independently:

"I did a job recently for some dolphins: they want me to make a video showing how to get rid of a bunch of troublesome seals.  Apparently, my cull will be recorded for training porpoises."

My friend Martin used to tell the best joke about New York cops talking at 'cross porpoises' - it only worked 'cos he did the accent so well. In the end he got sick of us drunkenly asking him to tell the joke everytime we got pissed together and we strangled the joke.