In my state, the electric utility has a program that gives away LED bulbs for free when you allow them to perform an energy audit on your home. The audit is usually done by a representative of an insulation or replacement window company, so that they have an opportunity to give you a proposal.
Anyway, I had the guy come in, and he replaced all of the incandescents with LEDs for free. The catch is, he would not replace CFLs, because they are already efficient enough, so I wasted an opportunity to get a few more free bulbs. If you save the incandescents that they replace, then you can share them with your neighbor to get more free LEDs, and so on.