[kylejt]

I wholeheartedly agree that we can send messages.

"THAT'S ENOUGH!" with a hand toward the dugout, sends a heck of a message. It's never failed me.

Dusting off the plate, and having a man-to-man with a catcher or batter works well.

Calling time, pulling out your lineup card, and calling the manager out works wonders.

Send the catcher out to have a word with his misbehaving pitcher sends a message.

Intentionally miscalling pitches or safe/out, is also sending a message. It's saying, IMO, the umpire has lost control, and this is his only way of dealing with things.