So I'll start off with a setup or feed-line and whoever makes me LOL the most wins and gets to start the next setup/feed-line.
I'd say the first 5 replies and I'll decide the best. But not sure how popular this will be or when I'll be back online again today 
A man walks into a bar carrying another man under one arm and a woman under the other...
Add a punch line to that. Not sure if this'll work, but yeah...
I found these midgets having sex in the bushes.
MAN
I've found you a couple of non-smokers
BARMAN:
Harry, you've got to let your ex-wife and her new husband get on with their own lives..
They were having a sale down at Slaves R Us.
BARMAN:
Sorry sir I can't serve you. You already had a couple too many
ouch. ouch. ouch.
Write your own jokes 
Quote: Rob B @ January 14, 2008, 1:16 PMBARMAN:
Sorry sir I can't serve you. You already had a couple too many
Rob wins!! I like the cheesy ones.
Now Rob, write a setup and then pick your favourite.
Yeah, Rob has my vote.
Gavin had my vote!
Not that my vote means anything but there you go!
Hmmm, oh I won did I. Not really my sort of joke thing, but hey ho
MAN RIDES INTO A SHOP ON HORSEBACK
SHOP ASSISTANT:
Hay?
Quote: Rob B @ January 14, 2008, 3:34 PMHmmm, oh I won did I. Not really my sort of joke thing, but hey ho
MAN RIDES INTO A SHOP ON HORSEBACK
Hi I`ve lost my Indian friend.
Oh you must be the alone ranger then.
It was a small shop... and a big horse.