Thinking outside the box' is ridiculous nonsense, since whatever you can do in a 'box' or closed environment is not 'thinking'. If I 'think' about a problem but limit my thoughts to certain dimensions - then i am not thinking at all, because thinking implies that one at least tries to take all relevant factors into consideration, and as there's usually no way to tell which factors are and which are not relevant restricted thought is not 'thinking' and so 'thinking outside the box' is simply a eufemism for 'let's start to think', but the metafor implies a hidden desire to return to conformity immediately.
Martijn Benders
out-of-the-box, thinking