think out of the box

It means to take a position or approach that is not the normally expected one. It is to see something differently than most or all others see it. It is to be unconventional in the face of conventional wisdom.

Exactly. It's also become something of a cliché in the business world -- being told to think outside the box is all well and good but for some businesses too much deviation from the norm could be a disaster (think things like accounting, which must follow certain protocols).