Where's your bagpipes ?
--Under my kilt.

Nice skirt.
--Do you know why they call it a kilt?
--Because that's what happened to the last person
--to call it a skirt.

Are you Scottish?
--All the best parts are...
(this usually leave the questioner puzzled whilst I make my escape...)

And my personal favorite:
Why are you wearing a kilt?
--I needed the room.