What're All Those Hand Signals?

In beach volleyball, hand signals are a very common sight. So what do they mean?

"One of the facets of beach volleyball is the use of hand signals by players to indicate to their partner what sort of play they intend to make. These signals are made behind the back, to avoid the opposition seeing the signals. Most commonly the signals are given with both hands by the serving player's partner before the serve, with each hand referring to the type of block the signaler will put up against an attack from the corresponding side of the court. Occasionally, however, signals are given during a rally. Generally, an open hand means the player will not attempt a block, one finger means the player will attempt to block an opponent's spike down the line, two fingers means the player will attempt to block an opponent's spike into the angle, and a closed fist means the player will block "ball," deciding where to set the block based on the set and on the opponent's approach and arm-swing. Wiggling the fingers on one of the signalling hands indicates that the blocker wants his or her partner to serve the player on that side of the court. If the server is a stronger blocker, he or she may run up to the net to block after serving. In this case, the signals given by the server's partner tell the server what type of block to put up."