I just launched a series on mental training for endurance athletes called "Going Within."
You can look up my post history here and see that I'm not some stranger dropping in to sell Nokia phones.
We may not all be athletes, or even fitness enthusiasts, but I believe we all have to deal with the subject of sustained concentration. Out on a long run, or perhaps during a challenging set in the gym, we rely on that concentration to achieve a higher level of performance. It's perhaps a little easier to be aware of that during bouts of intense movement.
However, we also need the ability to sustain concentration at work and at school. As someone who has the attention span of a three-year-old, I am always challenged to develop my ability to concentrate on the task at hand...and not on the other 99 tasks bouncing around my head or in my GTD system.
Anyway, I thought I'd share the series with everyone here as there may be some nuggets you can gleam for your own practice...whatever it may be.