If it pivots at the mid point the opening is half the door width. I can think of no advantage. Perhaps you are thinking of some other arrangement. A drawing would help.

Here is a youtube video of what I want to do. I'm trying to contact this company for a quote, but failing that I wondered if there was hardware available to make my own.

http://www.youtube.com/watch?v=4CVZ7l64vI0

Here is a link that might be useful: pivoting door

I don't think I'd consider what we're doing to be exactly like the video but we are adding a glass door between the main part of our house and the laundry room which is hinged at the wall and swings in and out. Sort of like saloon doors but NOT a saloon door. We purchased a single glass door and are installing it on bomber hinges (also called double action hinges) which we bought for $6.99 at Rockeler. I don't know if this will work for you but thought I'd mention it. My builder was unsure of doing this but my sister has the same system and every one LOVES it.
Hope this helps,
Sunny