Warning: this is not for the easily squeamish.
Well, I've known for a while that practicing Tae Kwon Do so much had caused pretty thick calluses to develop on my feet to the point where I could probably walk over hot coals without feeling it.
I bought a callus/corn remover the other day to take care of at least some of it. Well, I just used it for the first time and took off (and I wish I were exaggerating) a total of a ping-pong ball sized clump of dead skin. The scariest part? I still have plenty of callus left.