After discussing in a recent post how some folks have issues with pet peeves as minor as how a roll of toilet paper is hung, a friend pointed out the rather extensive Wikipedia entry on the subject.
Aside from the copious history of the debate (which makes this worth a read in and of itself), the entry cites two different published studies that make the claim that "Toilet paper orientation is often mentioned as a hurdle for married couples."
Interestingly enough, however, almost all of the surveys conducted on public preference for toilet paper orientation favors the over-hand method that I personally support. The debate has never been totally settled, despite the fairly conclusive data this presents.
At any rate, another rather fascinating concept presented is the fact that there are products out there called Tilt-a-Roll that actually features the ability to simply change the orientation of the roll quickly and easily.
Though the design is copyrighted, perhaps the inventors of Kosher Lamp, etc could come up with a way to market a Jewish Shalom Bayis-themed packaging.
After all, Tilt-a-Roll's company motto happens to be: "Let Tilt-A-Roll save your marriage!"