I've got a Vanessa & Louvier print, emulsion on metal, that at least appears to be a lensbaby or some kind of soft tilt lens. It's a gorgeous print, however they did it (one of the few "original" pieces of art I own).
They're tools. I dremeled the lens from a Holga, mounted it to a spring on a rail clamp, and shot a music video with it - tilt-shift holga with "film burn" from the open sides. Looked really beautiful. If I shot everything with it, it would be a gimmick though.