[mousepod]

Originally Posted by innerSpaceman

As Hitch rightly pointed out, the Maguffin is the object which the characters care greatly about, and the audience not at all. But the bargain between the film and the audience is made only when the characters care about the Maguffin ... and the movie is improved to the extent the characters demonstrate their concern for it.

I just found this "illuminating" article from yesterday's Columbus Dispatch:
Who's Got The MacGuffin?

to partially quote:

The best way to spot a true MacGuffin is to substitute anything else for it and ask whether the movie would change. If the microfilm in North by Northwest were papers or jewels or a safe-deposit box key, would the rest of the movie change? Not at all.
While the MacGuffin propels the story, it shouldn't be mistaken for an essential plot device. The shark in Jaws isn't a MacGuffin but a key character. It has to be a shark, or the story can't be told.
What about Indiana Jones? Are his adventures driven by MacGuffins?
Lucas and director Steven Spielberg think so, but, with all due respect to the most successful filmmakers in the universe, they're wrong -- at least by Hitchcock's definition.
To Lucas, the Ark of the Covenant in Raiders of the Lost Ark, the Sankara stones of Indiana Jones and the Temple of Doom, the Holy Grail in Indiana Jones and the Last Crusade and the crystallized skulls in the forthcoming Indiana Jones and the Kingdom of the Crystal Skull are the MacGuffins that drive the plots.
But if, as Hitchcock argued, a true MacGuffin is arbitrary and of no dramatic importance, none of the first three qualifies (we don't know yet about the fourth). The contents of the Ark mete out terrible justice to the Nazis in Raiders, a Sankara stone provides security for a poor village in Temple, and the Grail saves the life of Indy's father in Crusade. Each is critical to its story exactly as it is.

So I guess we'll agree to disagree. Or rather, I'll agree with Alfred Hitchcock... and you can agree with George Lucas.