I think yoga goes a long way to creating a stronger ability to concentrate on any task. I have been practicing Bikram yoga for 17 years, sometimes more regularly than others, but I find that it generally keeps me feeling focused and on task. If I start to feel easily distracted and unproductive, taking the time to do a class gets me back on track. In particular, the child's pose and the pranayama breathing makes a big difference in getting me in a good centered place.
Yoga creates a healthy distribution and dispersion on restless energy so that you can focus when you want and need to.
@ rita sharma: any other yoga poses for better concentration??