Recent versions of OSX have document preview in folders. You don't have to open a document to see its content.
What's also handy, is that you can import a graphic image into an iWork document straight from the folder Preview. Just click and drag. When green button with a plus sign and black arrow appears, the Pages document is ready to 'take' the picture.
It works with both column view (click on a file and see its Preview) and Cover Flow (slide show) view.
With Quick View it doesn't work unfortunately.