re: How can we get people to understand what the left lane is for on interstates?

I think George Carlin sums up my thoughts on slow drivers perfectly:
"Don’t you occasionally wish that instead of having headlights you had a couple of 50-caliber machine guns on the front of your car? So you could send several hundred rounds of burning lead into that slow-movin’ gas guzzler up ahead? Just incinerate the motherfricker and get his arse off the road permanently? Or don’t you wish you were driving a rented car, so you could bash the a-hole in the rear end, pay the deductible, and be done with the whole goddamn thing? BAM! BAM! BAM! “Don’t mind me, folks. I’m just tryin’ to ease him into second gear.” BAM! BAM! BAM! God, it would do my heart good. Or if the offender is directly behind you, wouldn’t it be nice to have an electronic message board that would rise up out of the trunk of your car and let you type in any message you like? ATTENTION, a-hole! YOU DRIVE LIKE OLD PEOPLE frick. SLOW AND SLOPPY!"-- George Carlin