Another idea with man on third:
If the ball stays close to the catcher and he has plenty of time to set up and throw to get the runnner, a savvy catcher can sometimes get the guy at third by appearing forget the runner on third and rush out, grab the ball, and fake the throw to first. If the runner on third comes on the fake, you have him. If not, there is still time to go to first.
Obviously, the catcher should only do this if he's got plenty of time to get the batter runner.