Switch Pitching

Question
Is there a rule for an ambidextrous pitcher in the majors on the ability to switch arms in the same inning or switch arms from one inning to the next?  I can throw with both arms equally as hard and with great control.  Do you feel this would be an asset to a ballclub?  Basically a 2 for 1 deal?

Answer
The pitcher may switch pitching arms prior to each batter.  Once he has established himself as a right or left handed pitcher for an at bat, he must finish that at bat pitching from that side before being able to switch.  While there may have been more, I can only recall one guy getting to the majors doing this.  He played for the Expos and I have no idea what his name was, which probably is a good indication of how effective he was.  The issue with this is developing players to be able to do it.  Once a kid learns he can throw 90 mph with his right arm, he's probably not going to put a lot of work into pitching with his left.  However, if a guy could master the art of doing it, it could be effective.  I hope this answers your question.