Before answering this question I checked out a previous answer and was not surprised to see an explanation of ADHD.  It seems that any discussion of a well known illness or disability gets responses from the explanation crowd and they often come with some good advice.

I have to say, that I agree with the idea of avoiding medication unless there is no alternative.  There are NO psychiatric medications currently approved for use in children under 18 that I am aware of.  The last report I saw on that subject was about 2 months ago and given by a well known psychiatrist.  The side effects of these medications in children and teens can be dangerous and counter productive.  Developing self discipline can benefit any child with or without attention disorders. 

Having said that I can also say that many adults suffering with these disorders have found good therapies, including medication, that help them be productive.  Glenn Beck, syndicated radio and television commentator, has discussed the issue at length in regard to his own fight with the problem.  One thing he was clear on is, like any medication, one size does not fit all.  He tried a number of medications before finding one that allowed him focus without debilitating side effects.  He also mentioned knowing others with the disorder who found other medications more useful for their conditions.

Physical activity and exercise are beneficial to everyone.  For the Hyperactive it is a way to burn of exess energy and develop focus.  For those of us on the other side of the coin, it helps develop the energy and focus we need to get through the day. 

The key to success for anyone is to find what you love and figure out how to get paid for it.  Whether it is sports, construction, art, writing, music, acting, organizing or any other activity there is a place for your passion in the business world.  It's far easier for anyone to focus when they are doing something they enjoy.

The most successful people in the world are those who chased their passion.  It's not an easy path and it isn't guaranteed to be successful the first time out but, persistence is the key to anything.  Rush Limbaugh has been fired more than a dozen times and been broke at least twice.  He followed the prescription of the "experts" for years with little success.  Only when he chose to follow his passion and do it the best way he knew how did he discover success.  The result was an internationally syndicated talk show with millions of regular listeners, ratings that match television ratings for the same time slot, the largest listening audience on radio and an exceptionally lucrative contract to continue doing what he loves.

George Lucas was told to keep his movies under 2 hours in length or Audiences wouldn't sit through them.  Peter and Paul LaLonde were told you couldn't make Christian movies with the quality of effects and actors that Hollywood provided.  Roland Emmerich(Independence Day, Stargate) though out all the film-making rules and created movies based on the elements he saw audiences respond to.

Find your child's passions, find out what kind of jobs include those passions, find out what is required to do those jobs and then help him focus on those needs.  Remember that over half of all millionaires either quit or never attended college.  Even fewer billionaires finished higher education.  These folks found what they liked and what they were good at and set out to learn what they needed for the job rather than focusing to much time on a broad course of education. 

I would like to suggest a little reading.  Peter Drucker's book The Effective Executive is a good primer on focusing attention on what works and what is necessary rather than try8ing to cover to many bases.  Rush Limbaugh's The Way Things Aught To Be has a lot of political commentary and getting the audio book will leave you focused on that.  In written form it covers a lot of details in regard to how he became successful by learning to do what he loved.  Dr Laura Schlesinger has written a number of books form both a psychological and biblical standpoint on discipline, self-discipline, self-motivation, and the big mistakes that keep people back.  Newt Gingrich's book To Renew America and the audio book Renewing American Civilization which is a tape of his lecture class at a Georgia University, both go into detail about focused learning and the use of specialty schools and technology to get training in specific areas without wandering off into the broad fields that traditional education uses. 

I have known a lot of people with college educations but, with the exception of MD's and Lawyers I haven't known many who worked in the field they studied.  Broad based education leads to a lot of knowledge in a lot of areas that have no practical use in the persons life.  While this sort of knowledge may make students more flexible it is also good at boring those who are focused on a goal.  For someone who lacks focus this can be a disaster.  Being forced to learn about things they have no interest in in order to gain knowledge of the things they are interested in is a great way to develop a drop out who lacks the skills for a good job and lacks the motivation to hold a job.