The secret to waiting for someone is to do something else. Play Angry Birds on your iPhone, write that paper for school, or start talking to a stranger. It’s not just guaranteed to keep you occupied (though, seriously, how interesting is it to look at the door every few minutes?) but also a 99% effective way to make Murphy’s Law work for you rather than against you.
Think back. Every time you were waiting for someone (to arrive or even waiting for them to be ready to leave), and you started doing something, they were ready the instant that you got really involved in whatever you were doing. Why not make that work for you?