Distributions of UNIX (GNU/Linux and BSD) are now used oftentimes as either a dual-boot feature on a PC or even the main operating system for enthusiasts, hobbyists and professionals. I have tried the majority (not all) of these common distributions, and I feel that it would help people to know the basics of a few and their skill levels. Find more at Distrowatch.
Ground zero level: (below true hobbyist systems, for mainly businesses without geeks)

Did you know that according to the Tennessee Center (which dug up some utility records) Al Gore's personal mansion consumes 20 times the energy of the average American home, which according to Al Gore's own numbers, consumes more on average than other homes in the world. According to the article, "The average household in America consumes 10,656 kilowatt-hours (kWh) per year, according to the Department of