A.S.
Boy scouts, community service at a nursing home/animal shelter/homeless shelter/children's hospital, enroll him in karate... all things will help him learn compassion, respect and self control. Give him more responsibilities and have a structured, calm and predicatale way of dealing with his behavior. Stop explaining each thing and follow through. Don't argue back. Be sure you are setting a good example of respecting other adults around you. Reard him for good behavior, catch him doing something good. We opften out more emphasis on the wrong they do then the good. Kids pick up on that and it effects they way they act.
Also, treat him with respect as well, it can have a lasting impression. A few helpful articles here:
http://www.selfgrowth.com/articles/InekeVanLint7.html
http://www.sfpcn.org/MS%20News11-09.htm
http://www.connectionparenting.com/parenting_articles/res...