Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
Is there any way I can stop iTunes opening when I plug an iOS device into my MBP

In iTunes, with the device connected and selected, look on the Summary tab, in the Options section for the option "open iTunes when this iPhone/iPad is connected".
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.