Dave,. .I believe you champion for bi-lateral symmetry, which only demands purity about one axis. Why discriminate against bi-horizontal or bi-vertical symmetry? Only a few people and creatures look the same upside down, and almost none of our machines do. What do we have that looks the same front-back?
It could be that you are looking, like those tortured 12th century philosophers, for metaphysical reasons to design a device, rather than good old fashioned practicality. Do I see a synchropter in this somewhere??
I myself would like to be sure that ships had their hulls on the bottom, airplanes had their wheels on the bottom, helicopters had their rotors on the top, sandpaper that is rough on only one side, and pens with ink only at the tip. This all seems quite nice to me, symmetry be damned! <img src="wink.gif" border="0">