Heh, a five-year followup has to be an IMDB record!
A red herring is something included in the story to distract you from what's really happening, but which turns out not to be important; the Arab guys in 'Flightplan' are an example. So is little Larry Sellers in 'The Big Lebowski.'
A MacGuffin is some damn object, the details of which aren't really important, but the fact that the characters are all looking for it drives the story. Each of the Mission Impossible movies has one; MI3 goes so far as to emphasize how amazingly important and/or dangerous the 'Rabbit's Foot' is, but never gives any idea of what it is or what it does. Hitchcock would have been proud.
It's a mess, ain't it, sheriff?
If it ain't, it'll do til the mess gets here.