Olympic swimming pools for liquids, times around the the earth for length and number of double decker busses for height.

You jest, but times around the Earth is the actual origin of the Meter. Kinda.

The history is quite interesting and well worth checking out.

I can't recommend a book on the subject, but I do heartily recommend "Longitude", which is about the challenges of inventing the first maritime chronometers for the purpose of accurately measuring longitude.

The original meter (1790s France) was defined as 1/10,000,000 of the distance from the equator to the North Pole along a meridian.

Not sure if you're correcting me, but yes, that is "a" path around the Earth.

It's not the most aesthetic one, but it was at the time the most able to be measured.

For smaller lengths and radiation bananas are also acceptable.

A good physicist can calculate banana equivalent dose other head. Always ask for it when dealing with radiation.

Don't forget packs of cigarettes as a more convenient unit for measuring volumes significantly smaller than Olympic-sized pools.

There is, of course, no more need to standardize on a specific brand or style of cigarette than on a specific depth of Olympic-sized pool.

Don’t forget cheetahs for velocity and elephants for weight.

A horse as a measure of power and a crocodile bite as a measure of compression strength

Or vice versa.

I thought all measurements in data centers were in US football fields.

For the floor area or length/width it is, but if you want the height then that's in Empire State Buildings.

There are standard units, yes.