Traveling With Your Guitar on an Airplane

I am going on a business trip at the end of the month, and I would love to take my guitar with me, but I am not sure exactly how to pack it for the airplane.  I asked the owner of the local guitar shop if he had any travel tips for guitars.  He told me that it is very easy to travel with your guitar.  All you need is a nice hard case to carry it in, and make sure it stays on top of everything so that it is not smashed.  Sometimes, depending on the airline, you can use it for a carry on.