In my short kilted experience, I've been asked mostly the standard, amusing questions:

Are you Scottish?
Why? Was my accent a dead giveaway?
(this is usually asked when I'm in a conversation, and it's obvious, through my (south-central Pennsylvania) accent, that I am not)
OR
No... I'm on a quest to wear attire from around the world... next week it's primitive peoples of PuaPau new Guinea..

Are you going to a rennfaire?
What's a rennfaire?
(Usually followed by total silence)

Do you play the bagpipes?
No, that privilege is reserved for the intelligent, amongst us.

What's with the knife? (pointing to sgian)
It's actually a ceremonial suicide knife, in case we are overwhelmed by lusty ladies asking "the question".

What does your wife think about you being in a kilt?
The better question is: What does she do when I'm out of it?
(accompanied by a lecherous smile)

How do you go to the bathroom?
Uh... didn't your parents teach you this yet?