David Brandt of the AP suggests that baseball switches to wireless communication to prevent sign stealing:

A partial model is already in place: The NCAA’s Southeastern Conference has used electronic communication between coaches and catchers during league games for the past two seasons, which allows the coach to talk strategy with the catcher through an earpiece. It’s much like the NFL, where an offensive coach tells plays to a quarterback.

No hand signals needed.

“I don’t know why everyone isn’t doing it — it’s fantastic,” LSU coach Paul Mainieri said. “It allows the coach to speak directly to the catcher and speeds up the game.”

Chron.com

Of course, these signals could be hacked, so the connection would need to be encrypted. The downside would be the loss of funny videos showing the third base coach going through the signs.