Go Metric

Most Americans use the old traditional system of feet, pounds, and ounces. We are in the small club consisting of the US, Liberia, and Myanmar. With a little experience, it is easier to use. If someone says the metric system is just too complicated, ask them how many ounces are in a gallon. I will tell you later.
Back in the late 70's, there was an attempt to convert us to the Metric system. It failed. There were educational commercials to explain the system. They concentrated their efforts on conversion factors. If you use the system, you don't use conversions. Just give someone a recipe in metric units, and a metric only measuring cup, and he will get the idea. They talked about a kilogram is about 2.2 pounds, and a cup is about 250 milliliters, and a liter is about 33.9 ounces. It does not matter. It helps to have an approximate idea, but then you just get familiar with it. About 1980, the Reagan administration killed it.
I like the Celsius temperature scale for the simple reason that it relates to human experience:
30 to 40C = 85 to 104 F, Hot
40 to 50C = 104 to 122F, dangerously hot
above 50C = 122F, Deadly
20 to 30C = 68 to 85F Mild, nice
10 to 20C = 50 to 68F, cool
0 to 10C = 32 to 50F, chilly
-10 to 0C = 24 to 32F, cold
I am out of fine distinctions for cold, but you can feel it. 77F is 25C, and it just above average for home thermostats. The only problem I see is the negatives are too common. I can give you the temperature in Celsius within a few degrees by feel.
By the way, our average body temperature is not exactly 98.6F. That was a conversion from 37C, but it varies from person to person, and that was the rough value. It was not 37.0C. Note the lack of a "significant digit". In scientific writing, 37 means "36.5 to 37.5" but 37.0 means "36.95 to 37.05."
One thing that might convince folks about the value of the metric system is that it never uses fractions. If you need the next size wrench, it is easier to look for the 12mm, than to think about how the next size from 7/16" is 1/2", or maybe 15/32".
NASA lost a $125 million Mars Orbiter because one contractor used pounds, and the other used Newtons.
http://www.cnn.com/TECH/space/9909/30/mars.metric/
Today we sue 2 Liter bottles, cars are made in many countries, and we are somewhat familiar with Metric. It is time we switched. Maybe we should start with the schools. Do all science in metric.