If you are planning to cheat at chess using a computer you should at least try and be clever about it. The latest cheating controversy involves a player in the Imperia Chess Festival, who seemed to be playing extraordinarily well for some one with a 1600-ish rating. This in and of itself is not proof of cheating, although the Chief Arbiter did the sensible thing and investigated the player concerned.
After a scan with a metal detector, it was discovered that the player, Arcangelo Riccicardi, had a camera in the pendant around his neck, and was receiving assistance from a confederate who was replying in morse code to a receiver hidden under his armpit. Some of the tell tale signs, according to the arbiter, was that he never left the board (as most players do), and he blinked when he was trying to decipher the messages.
Of course the player was expelled from the event, and an investigation is underway. Probably the most interesting thing about this case (to me anyway) was that the method of detection was more akin to how a casino would spot a card counter, rather than through any chess related detection. Of course the good results were a tip off, but it was the amateurish approach that seemed to give the game away.