I'll tell you what I did to counteract this. I am a firm believer in if you can dish it out, you can take it.
Good example is someone once made fun of my walk, (I tend to bounce because of how I land on my feet.)
Now being the d%$khead submariner I am, I simply smiled, and simply said jokingly, "Hey, as long my nerves are in working order, the walk stays man", referring to a constant twitch he had in his face.
Of course this probably not the best thing to say if you're worried about political correctness and being nice. Not saying it's right to make fun of someone, but I do believe if I can't laugh at myself, who am I to laugh at someone else.