Blink: The Power of Thinking Without Thinking by Malcolm Gladwell

A good book, basically it talks about improving one-self up-to the point that one can do a task, perfectly without even thinking of it.

Also I have recently seen an interesting documentary about the savant syndrome, and it seems that the research in this field may one day provide us means to develop our mind in the most unusual ways. Ex: the Chinese scholars that practice long computations with the abac, after several year, they can compute without the abac long computations, without even not thinking about it, by a simple movement of the hand.

Also interesting enough is the other side of the story, the more you develop your inner side, the more it is possible to affect your means of interrelation with other people.