Let me suggest you an interesting article in the last Harvard Business Review issue.
It’s called Breakthrough Ideas for 2007, it’s available for FREE in the HBR web site: it’s an annual survey about what this important institution considers as the set of great emerging ideas.
In particular, I found interesting the part called When to sleep on it . Here is the beginning of the article:
Psychological research shows that conscious deliberation, however long and careful, can be a surprisingly crude and ineffective tool, because the conscious mind has a very limited processing capacity. […] Luckily, there is another way to make difficult choices: Don’t think hard about the decision, and after a while your unconscious mind, which is known to have a far greater processing capacity than your conscious mind, will tell you what you should do. Such an unconsciously generated preference is usually referred to as intuition or a gut feeling.