Zen is right. The MacGuffin is interchangeable, the whole story doesn't hinge on the specifics of the MacGuffin. If the Maltese Falcon had been a Dzi Bead from Ulan Bator it wouldn't have mattered to the story, but some kind of MacGuffin is needed to move things along.
Maybe it is the plot equivalent of fiber in your diet. Could be Metamucil, bran muffins or psyllium seeds.
For me, clearing the decks and coming about is a sailing reference but it means that I am purging a lot of material things from my past careers and hobbies and making preparations for a change in direction.
http://en.wikipedia.org/wiki/Coming_about
To be more accurate, my current maneuver is probably more akin to a jibe:
http://en.wikipedia.org/wiki/Jibe
If it weren't a big change it wold be some other chaos creating event. I seem to exist in a perpetual state of chaos and I am now trying to remove the chaos from my life.