I was first introduced to The Flow (as such) sometime ago at a leadership training. It goes more or less like this:

The concept (apparently borrowed from psychology) states that, when you are faced with a problem, project or activity challenging enough so that you use a significant percentage of your skills and analytical horsepower, you will enjoy doing it. You enter The Flow state of mind, where you may loose track of time. You will be very focused and get less distracted by insignificant details and the outside world. This happens to professional runners when racing, to chess grand masters during a good game, to programmers when coding a complex algorithm not found in any book, to professional golfers during a good round, to researchers when developing that new exciting theory.
Facing an excessive challenge for which you are not prepared enough could get you frustrated or stressed. On the other end, working on something which doesn't exploit your skills or talents will probably get you bored or unmotivated.
If you are a good leader, you will do everything you can to have all your team members in The Flow zone, at least most of the time. You will also make sure to develop your team and keep giving them bigger or different challenges every time. If you are a good mother or father, you will want your kids to experience this as often as you can (of course, they need to play too!).
Building up. My take on The Flow.
There are some persons, however, that do not like challenges as much. They don't need to progress. These are type-B persons. Bs stay wherever their comfort zone is and don't move up in the graph. They are usually the same ones who fear (and oppose to) change. They like the status quo, they are happy to stay with what they know or have and are afraid to try anything new or take any risks. They can be average runners, but will never become professional runners, because it takes too much effort to get there and there is no guarantee of success. They don't get bored doing repetitive left-brain tasks. They don't like the idea of learning from their own mistakes.
Then, there are As. They need be challenged all the time. They are always trying to go up in the graph and don't like to stay where they are. They are ambitious. They can't stand not using their right-brain. They become stars at whatever they do (they won't do something they can't thrive at, at least not for long). They are always learning, reading, teaching and developing their skills. They keep taking bigger challenges every time. They know what their talents are, and exploit them as much as they can. These are excellent programmers, writers, leaders, entrepreneurs, researchers, professional runners, golfers, chess masters, you name it. They learn from their mistakes.
In some (most?) organizations, there are jobs designed for both As and Bs. They claim they need Bs (pun intended) to do those B jobs (that As won't take), and that those B jobs are necessary for the business to run well. They sometimes put As to do B jobs and vice-versa. Consequences are usually pretty bad.
What they don't get is, they probably experience these problems because the people that designed the organization, processes and roles did the mistake at the first place. Or they hired the wrong guy. Why have B employees? Why have B jobs? What's the value of a B job? Can they buy that service or product from someone else? Can they create a new, different process? Or use innovative technology that automates it? Can they outsource it to another company that can?
Bad processes and ideas stick around for long time because they are hard to change (probably because of the same type-B employees?) once they become the standard way of doing things. In the Software Engineering discipline, it is well known that a mistake during the requirements gathering, analysis or design phase will be much more costly to fix than a mistake on the implementation phase (aka bug). I claim that this rule is also valid when designing businesses, organizations, processes and roles (it also applies to, for example, building houses).
When starting a new team or small business, is there a way to design the organization and its processes so that there are no type-B jobs?
Are you a type-A or type-B person? Do you like working with Bs? Bs are usually boring, because they tell the same story every time.
I admit, there are some bad generalizations here. They are a cheap way to induce your comments and also to make my point. In reality, matching roles and their challenges with employee skills and talent is tough and it is not an A or B binary problem. But it is the willingness to improve, to develop and to take different and bigger challenges everytime that makes the big difference.
Besides this generalization, is there a way to combine employees, jobs, processes, projects and roles so that challenge, skill, knowledge, talent, analytical horsepower, creativity, potential and human capital investment and development all come together to an optimal maximum?
In the Flat World, and when Small is the new big, is there a point in creating a small business that will need hire type-B employees? I don't think so!
So be small, dream, think and design big, then thrive implementing it with As. Now go change the world! 