Oncefallen posted a fine document! But in that document is not defined of what a salute truly means or represents. So please allow me to define the meaning of it, for those who wish to understand.When you put out your hand in civilian life, your intent is to greet,but before this was done,it really meet long ago,that you had nothing in your hand in which to hurt another with! hehe
The salute to most mean simple acknowledgement of a rate or rank,but in reality it goes far beyond this simple movement.It defines ones loyalty to another,to respect another who's love for this Country is as great as yours! It represents a love of the people we serve,to remind them that even if they have never been in the service we salute all who love and are loyal to our nation!
A salute show one has all things we believe in common about our Country! Having a cup of coffee in hand during an acknowledgement of this, is like dealing with a cashier at a counter being on the phone.It is rude! And by what you are doing, you are telling the other person they have no real meaning to you. Is this taking this a bit far? i guess one must care to understand this.
So the next time you see someone saluting, or the next time you wish to honor someone by saluting, you know not only what you are doing, but why you are doing it! hope this helps.