3D printing company i.materialise has produced some beautiful user-designed lamps using their RP methods, like the three above (designed by Tom Cluckers, Oleg Kurtsev, and the duo of Pieter-Jan Debuyst & Laurens Dekeyser, respectively). Now they're selling a lamp that provides user customization within their own design: The Appear Lamp.
Made from polyamide, a material that's like nylon laid down with SLS, the $99 Appear features text of your choosing atop the lamp, and hidden within the lampshade itself; choose the font, type your own phrase, and i.materialise does the rest. The lampshade appears blank until the light's turned on. Check it out here.