I've seen the term "corpse hopping" used regarding some behavior on the higher difficulties of Diablo III. What does that mean, and how is that done?
It refers to an abuse of game mechanics to get to a certain destination without having to kill monsters on your way there.
It only works with at least two players and the procedure is as follows: You run as far as you can, and die. You stay dead. Since your standard in the camp can still be used when you're dead, your partner can teleport to you, run/leap/teleport/etc (hence "hopping") a little further and die again. You revive, go back to camp and use his standard.
Repeat this a lot and eventually you'll end up at the destination where you want to go (boss-fights, for example).