I remember Courmayeur as a sleepy little town just before we got to the Mont Blanc Tunnel. We stopped there for lunch on our way from Milan to Chamonix. We got there around 1:00PM and I was surprised as all the restaurants were closed for the afternoon.
My father bought a case of wine there (against the advice of our French host) and it was awful.
Their web site is here and the wikipedia article is here.