Thanks for the great technical response. You know your stuff. Are you an engineer of some type?

Can I ask a few more questions, so that I can really wrap my mind around this concept:

1. So is there a difference in the brightness of an led when powered by different voltages?

2. You said this: "The practical route: All the dangers shouldn't be a problem, and if they're really rated for 2v each, an additional .2v shouldn't be a big deal, but who knows. If you burn down your house and soil your pants, I warned you."

Where does the .2v number come from? Is that the resistance of an led?

Thanks again!
James