I never really understood why weight is such a big deal anyway. Think of it in comparison to your body weight.
Better yet, say you carry 2 quarts of water on your bike. How much faster are you when those 2 bottles of water arn't there? That's about 4lbs of weight right there.
I know weight makes a difference, but I don't think it's as big of a deal as the "weight weenies" think it is... but who am I?