When playing a doubles match in a tournament my partner and I were using pretty standard signals where the net player would signal his intentions--whether to cross, stay or fake. In one match we were amazed that every time we signaled to cross our opponents would return down the line, every time we signaled to stay or fake our opponents hit crosscourt. Were these guys psychic? Then my partner noticed a guy sitting in the stands. 'Hey, wasn't he on the other side last game?', he said. We realized that when we changed ends of the court so did he, and he was relaying our signals to our opponents. So we had to change our signals. During the change over we came up with more innocuous signals. Instead of the standard open hand, closed fist, etc, we would tug on the right shoulder of our shirt to signal cross, tug the left side to signal stay, spin the racquet in our hand for a fake. But before we started with the new signals my partner couldn't resist showing the guy that we were on to him so when he went up to the net and put his hand behind his back instead of signaling as usual he flipped the bird then turned and looked right at the guy. It was priceless. We did go on to win the match and did not shake our opponent's hands. After that any time I played doubles in a competitive match where there were spectators my partners and I would come up with unique signals, and often change them during the course of a match. Signals could be as subtle as adjusting your cap, flipping a racquet, pretending to adjust strings, you name it. It was actually fun constantly coming up with new signals. What signals do you use?