If I need to peel myself away from Diablo III, it's usually convenient to do so at a checkpoint so when I quit and rejoin I'm plopped down right back where I was (or equivalently in a randomly generated area). The Checkpoint! messages though are quickly forgotten unless one cares about them (and I usually don't).
How do I know where my most recent checkpoint is (without quitting and rejoining, possibly losing a fair bit of progress through a level)?