I know this isn't supported by Blizz officialy but I thinks ok to post how to do it. If not feel free to delete this post.
I finally figured out how to dual box in diablo 3 after weeks after interwebz searching. I made a quick little video tutorial to show how to set it up.
Edited by GamerLCD#1675 on 7/15/2012 1:51 AM PDT
Threats of violence. We take these seriously and will alert the proper authorities.
Posts containing personal information about other players. This includes physical addresses, e-mail addresses, phone numbers, and inappropriate photos and/or videos.
Harassing or discriminatory language. This will not be tolerated.