Remember those magnets you tie-wrapped to the fuel line that changed the molecular structure of gas to give you another 10 MPG? Well those big suckers are magnets.
Seriously, though. I was bored and curious and spent a half hour trying to look this thing up and figure it out. I couldn't even find in in a parts book, though Ford does have pictures of it. I would guess it's to dampen vibration that could cause damage to the plastic intake manifold and its rubber gaskets. But that's just a guess. Anyone?