[Chicken]

I read somewhere that because low-energy lights give off less heat, the heating in your house runs slightly longer to compensate for that, and as a result almost completely negates any energy saving you think your making.

Anyway, as homealone has said, once manufacturing & disposal has been added into the equation, I'd be surprised if there's anything like as much of a saving of energy as seems to be made out... and trying to find out the energy used in manufacturing them is like trying to find rocking horse do-do in a proverbial stack of needles.