That's pretty cool, I wouldn't have thought of using 3 Y-adapters. I think a lot of people would already have an old lamp laying around too, so they wouldn't even have to buy one.

I'm working out the details for a system that can get you vegetating 12 plants indoors for a SOG type setup for about $50, assuming you have seeds or clones already. That includes lighting, containers, and 3 gallons of dirt per plant. The great thing about this system is if you can't afford a HID light just yet, you can buy just the bare essentials and then buy the rest later as you can afford it. This system does assume that you will eventually buy a HID light for flowering. I'd like to run it from start to finish before I post details though.