The question is misframed. You need to use the Charlene Li/Josh Bernoff "POST" model for social design from Groundswell: People, Objectives, Strategy, Technology. You are starting with lightbulbs, the technology, which should come last. Here is the right model:

• People: Who are the people with a stake here? What are their social technographic profiles? What is the distribution of creators, collectors, critics, joiners, spectators and inactives?
• Objectives: Are they really looking for "light" or might they be looking for heat, cold, a breeze or a nice smell instead? Have you even bothered to listen to the opinion leaders from this purported light-seeking community?
• Strategy: As Charlene and Josh say, plan for how your relationship with the community members will change. Will you still think they are pretty in the harsh incandescent light? Have you considered that your target audience may already have gathered under an existing lightbulb somewhere, that you have no hope of displacing? Perhaps you should just help pay for the electric bill of THAT lightbulb.
• Technology: FINALLY you can get to technology. Assuming you've validated that a lightbulb is, in fact, what is needed, your POS steps will have revealed to you the type of bulb (compact fluoroscent, incandescent, LED) you need, the power source, who has admin privileges to turn the switch off or on, the appropriate participatory model for screwbulb tightening etc.

p.s. Josh, you already commented on my review a couple of years ago at http://www.ribbonfarm.com/2008/0... ... if Charlene sees this, I hope you like the review too :)