A wonderful first post.
This is how imagine that conversation going:

http://homepage.mac.com/etek/.Pictures/christopherwalken.jpg

Han: "Chewie, I noticed you have no tail. What happened?"

Chewie: "You know, they cut it off when we're puppies. It's called docking the tail."

Han: "That's too bad, you know. Think about it; it would be so great to have a tail. People could tell when you were angry. They'd go, 'Get back! Look out! Don't fuck with Han today; look at his tail.'"

Chewie: "I think you mean happy, Han. Wookies wag their tails when they're happy."

Han: "Oh well, maybe you. But if I had a tail, you have to be expressive with that tail, otherwise, what's the point, right. They'd know, they'd know. They'd go, 'Get back, don't bother Han today. He's having a bad day.' 'How do you know?' "Well, did you look at his tail?'"

(Hours later, it comes up again. Chewie asks Han a question.)

Chewie: "What would you rather do: have a tail or the gift of flight?"

Han (immediately): "Oh, have a tail! Come on, that's the dumbest thing I ever heard. You can always get on an airplane, but a tail . . ."