In the 21st century, it is surprising that there is a minority of educated people left on the planet that don’t know how to use the unit system of the modern world, Metric. These people generally live in the US, Liberia and Burma. Even NASA has recently declared the moon to be metric, so it seems time is well overdue for the US to drag themselves thru the 19th and 20th century, and into the 21st.
Having spent the last 20 years using the US ‘system’ on pretty much a daily basis, I have a good idea as to which system is more elegant, easier to learn, and more practical.
Sounds logical don’t you think?
Interesting. 
In all seriousness, something really helpful in learning and using the Modern Metric System, is this wiki about [url=http://en.wikipedia.org/wiki/Metric_yardstick]Metric yardsticks based on everyday objects[/url]
Length
* One meter equals roughly one (longish) step of a tall adult man. Two cubits as perceived by such a person may come to about one meter.
* The length of a one-second pendulum is approximately one meter.
* One kilometer equals ten minutes’ walk.
* The distance between nails of fingers pressed together is roughly 1 cm or 10 mm.
* the width of a fingernail is roughly 1 cm.
* The cubit arm (forearm from elbow to fingertips) is roughly 50 cm. This is known as metric cubit and has been used in some countries.
* The width of man’s hand is about one decimeter or 10 cm. That is almost the same as the old English unit “hand”.
* The side of a matchbox is 5 cm.
Area
* A large soccer field has an area of one hectare (10,000 square meters).
* The area covered by a large umbrella is roughly one square meter.
Volume
* A cube of one hand (1 decimeter) per side is equal to one liter.
* A drop of water (or water-based solution, like milk, tears, etc.) is very close to 0.05 milliliters. 20 drops make one milliliter. This is an approximation used in chemical engineering. One liter is therefore roughly 20,000 drops.
* Both the British and American pints are close to 1/2 L, sometimes called the “metric pint”.
* Soft drinks are sold in 1, 1.5, 2 and 3 liter bottles.
Mass
* One liter of water weighs one kilogram, and therefore 1000 liters of water (a cubic meter) weighs 1 tonne.
* One tonne (1000 kg) is roughly the mass of an economy motor car.
* One U.S. “nickel” (5 cent coin) has a mass of 5 g.
* One litre of soda has a mass of roughly 1 kg.
Force
* A small apple on Earth exerts a force due to gravity of about one newton (N).
* One kilogram at the Earth’s surface exerts a force due to gravity very close to 10 N.
* One newton-meter torque is roughly the increase in torque by adding a small apple to the end of an outstretched walking stick.
Temperature
* For Celsius temperatures
o 30 is hot
o 20 is nice
o 10 is chilly
o 0 is ice.
* Normal room temperature is roughly 22 °C
* An outside temperature of 300 kelvins means bikini weather.
Pressure
* Normal air pressure at sea-level is around 100 kilopascals. It equals approximately 1 kg/cm2
* Every ten metres’ depth of seawater exerts about one bar or 100 kPa or 1 kg/cm2 of additional pressure.
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) or maybe not, we always need something to flog them with. and poor burma.