Since 1967, the ability to think 'out of the box' is known as 'lateral thinking'. A scientist need to be creative and to think outside the dogma to solve new problems. How to get to the eureka idea? According to Douglas R. Green, you are going to hate the answer:
Read. A lot. Read everything you find interesting, inside and outside your field, and then read everything else. By “read” I do not mean look at the abstract (although that is a start) or download the PDF (ditto). If you are reading five to ten papers per day, you've got the gist of it. If you are new to this, it is very slow going at first, but you can get very fast at this, really. Here's why this is so crucial. Creativity, as near as we can tell (I've read about this), emerges from a combinatorial process in which bits of information are rearranged and extrapolated at a subconscious level—think of it as a conceptual smoothie sloshing around in your brain. Then, when you happen to think about something you have noticed in the lab, wondered about in the literature, or worried about late at night (you do this, right?), there emerges an “aha” that might explain something that has never been explained before
source: Green 2010 Molecular Cell
Now comes pubmed. Yesterday pubmed was exactly the opposite of thinking/reading lateral: put a keyword and follow the abstract flow. With great pleasure today I discovered Pubmed Images: it is like google images, put a keyword and start reading transversal to the article and start a new story. Enjoy lateral pubmedding.