I think my most useful skill is mediation. My boss is not the easiest person to get along with. His ego really needs stroking sometimes. As a result, I can clue in visitors as to his mood and the best way to handle him.
Another useful skill I seem to have developed is anticipation. I love to see the look on his face when I hand him something that he's fixing to ask for.
Recently, we moved into a new area in the building. One of the first things I did was to change the information board in the lobby to reflect our new room number. A day later, he finally thought about it and was half way through asking me to do it when he looked at me and said, "You've already done it, haven't you?"
It's great!
JusPeachy 
