I could see this a a potential DIY project - paint bulbs black and then carve some of the paint off to let the light shine through. While not specific for outdoor use, these Astral Lights would be a lovely addition to an enclosed porch :)
The Hyphae lamp is a series of organic table lamps based on how veins form in leaves. Each lamp is a completely one-of-a-kind design in nylon plastic. The lamps are lit by eco-friendly LED's and cast dramatic branching shadows on the wall and ceiling.