George Carlin asked a great question:
"Have you ever noticed that anybody driving slower than you is an idiot, and anyone going faster than you is a maniac?"
This isn't just about driving--although that is an excellent example--but about the way we view others in terms of how they worship, what they eat, what they drive, how they earn a living, their musical tastes, their entertainment choices, the things they read, how they spend their money, how they raise their children, the things that motivate them, and...well you get the point.
The list is endless. There really is no limit to the areas in which we are willing to judge others.
Here's an idea. Just for today, determine that you will not judge those around you.