Not more than 2 days ago i was working on this exact problem myself.
Well it depends on the lock i guess.
I have a lock in which, if the key is inserted on one side, and you pick the other side - you can actually turn both plugs if you use some kind of a wire or a pick to get both cylinders 'stuck together' (you have to constantly apply pressure to the wire/pick), and while turning the plug without the key, the other will turn simultaneously.
There was a thread about something similar a while back:
http://www.lockpicking101.com/viewtopic.php?t=5885
Cheers, and good luck.
Please share if you discover something that was not mentioned
