My A.J always gets very excited when people come over. If he had it his way, he would greet everyone with a big 'ole lick across the face!
We don't mind it too much but most of our friends and family don't really care for it. We've handled the situation by talking to our friends and letting them know that they need to be calm around him and not wind him up. Also, we've let them know that it is fine with us if they are stern with him and tell him NO when he's doing something they don't like. In my opinion, I want my dogs to know that they have to listen when other people discipline them, not just me.