where are you talking about? because in america there is no such thing as the fast lane, contrary to popular belief. the left lane is the passing lane. but even in the passing lane, you cannot exceed the speed limit. it is simply there to pass in front of people who are going under the speed limit which is perfectly acceptible and legal.
to answer the question, if you are in the passing lane, you must be passing someone so it wouldn't make sense to move over for someone else who is also passing. they should not be going faster than the speed limit either. this is true, i know people who have gotten tickets going slightly over in order to pass. the cops say so, you have to do it. if you happen to be driving in the passing lane, shame on you! move over and let the passers pass. but again, no speeding allowed.
tailgating would not make me go faster. if i need to stop for some reason, an animal or child running out into the road, the tailgater is going to be buying me a new bumper and whatever else on my car i fancy. geez people, just don't do it. chances are you'll get behind an asshole like my dad who will stop short cause you're pissing him off and the person behind is always at fault in those kinds of traffic accidents. his car is already falling apart; he doesn't care if your insurance goes up for being a dumbass.