Hey, you guys don't want to talk about robots, so I figure you might want to gab about men's toilets. Cecil has the Straight Dope:

The rear wall of the typical urinal is parabolic in cross section when viewed from above, and the porcelain finish is conducive to laminar flow. The principles of fluid dynamics tell us that a fluid striking a smooth surface at an oblique angle will tend to flow along that surface. Assuming the source of the fluid is near the focal point of the parabola--and modesty makes it unlikely he'll stray too far--the fluid will run straight down the urinal wall with little or no splashing.