My favourite (can't remember if it was JWs or Ms) was to tell them I was a satanist and it was such a lovely coincidence that they had called by as we were just about to start the safrifice...

Latest one and much more effective, only a few weeks back.

Ding-dong

Me: Hello, can I help you?

Them: Yes. We wonderered if you had ever thought about God.

Me: Oh yes. All the time.

Them (surprised): Oh! What do you think about?

Me: Well, when I say think about I don't realy mean it (they grin in their innocence...) I actualy speak to him all the time. He always ansers me.

Them (shocked by now): ...and what does he say to you?

Me: That my religion is right of course. All others are wrong and will face eternal damnation unless I welcome them into my faith. The initiation is realy quite simple. Now then, where is it... (looking round and picking up an old duster I spot on the shelf). Ah, here it is! Now, please just stay still while I place this on your heads...

Them (hastily backing out of the garden gate): Oh, no. thank you. We can't...

Me (Chasing them own the road): Come back! Repent ye sinners. Be welcomed to the holy church of... (Break into fits of giggles)

Eeeeeeeh. Good fun. The Mrs hates me answring the door.

Did I ever tell you about the two cavity wall insulation salesmen who spent two hours selling us their product when we had no cavity walls?

:-)

Cheers

Dave