My dad was a roofing contractor. Growing up he use to say, "A hammer fixes everything." And in his profession he was more often right than wrong. In the environment of laptops, blackberries, iPods and other such tools...a hammer is not as useful, that is if you think of hammer in the traditional sense.
What I have come to realize is that every generation has its hammer. With computers it is "ctrl-alt-delete." Or if it gets really frustrating you pull out the sledgehammer of our age...unplug, yank the battery and reboot. This almost always "fixes everything."
The same 'hammer' concept seems to work in the making of movies. I viewed Knowing this week-end. It was an excellent movie. Kept me on the edge of my seat. But then came the ending. It was a movie that had one of the weakest endings I have ever seen. It seemed that they weren't sure what to do, so they pulled out the "hammer." I don' want to give the movie away, but suffice it to say when you don't know how to end a movie it seems you throw in a UFO or catastrophic event...or both! If I would have had a hammer I would have thrown it at the screen.