I read that teaching them to speak and then rewarding them for being quiet on commmand is a good way to control barking. I don't know this to be true, I just read it somewhere.
I'd try to figure out why he is barking. Is he ordering you to pay attention to you? If so then your problem is a dominance issue and not a barking issue.
Here is a link to the Dog Whisperer website, I believe he addresses tis issue.
http://www.dogchannel.com/experts/ce...aspx?WT.srch=1