LED bulbs are the best lighting choice

Pop Quiz: Watts, lumens, luminous efficacy and Kelvin temperature. Can anyone in the audience define each lighting term and how they relate to each other? Is a 1200-lumen bulb brighter or dimmer than a 100-watt incandescent? Will a 2780 K "warm" light accentuate my hazel eyes or make my skin look pallid and blotchy? And, are these snazzy new $40 LED bulbs efficient enough to justify the upfront cost?