One of the most fascinating things to watch on an Everest expedition is the Puja Ceremony. A ritualistic prayer/blessing session led typically by a buddhist monk (or a few). Lots of chanting, bells ringing, incense burning, and alcoholic beverages. To westerners it is a beautiful thing to be a part of and it helps bring the team closer with each other and with the Sherpas. To the Sherpas it is a necessary ritual that needs to be done or else they won't climb up the mountain. It is a way of paying respects to the mountain gods.
http://www.youtube.com/watch?v=kbUFGrVFdWk