I also built a reversing ring for my Canon 50-mm lens that can go onto extension tubes or the bellows. In this regard, digicams have a long way to go before they really equal conventional photography. But some subtle effects are at work here, too. People are conditioned to respond differently to the film color gamut, the TV color gamut, and the print color gamut. I think one of the reasons that people like the photos from the Canon PowerShot 350 so much is that it's biased toward red, kind of like Polaroid film.
People look healthy and everything has a warm glow.
Film also tracks differently as light areas transition to shadow. Reciprocity failure and other effects having to do with the density of emulsions are at work both in the film and in photographic paper to give a different feeling of depth than you get with TV-like imaging devices and ink jet printers. Putting the same thing on film gives it a somewhat disembodied feel, while warming up and saturating the colors. It's more engaging and more dissociated at the same time, because you know it was shot at some prior time. Kai's Photo Soap comes pretty close in emulating a film look, with its various sliders and adjustments.