Part of a Roman soldier's pay was called salarium argentium, "salt money", which was used to buy the then-precious commodity, and so pay today is called a "salary". (source)

In Kublai Khan's China, anyone who had crops struck by lightning was excused taxes for three years. This was not selfless charity, as the Chinese believed that lightning was a sign of God's disapproval. So, if the Khan had accepted money from someone who had incurred God's wrath, he could have brought ill fortune upon himself.

In June, 1776, some workmen who were repairing Winchester Cathedral discovered a monument which contained the body of King Canute (also spelled Knut). It was remarkably fresh, had a wreath round the head and several ornaments of gold and silver bands. On his finger was a ring, in which was set a large and remarkably fine stone, and in one of his hands a silver coin. The coin found in the hand is a singular instance of a continuance of the pagan custom of always providing the dead with money to pay Charon. (source)

Parker Brothers prints more money each year for its Monopoly games than the U.S. Government issues in real currency.

It is reported that the Hagia Sophia (Church of the Holy Wisdom) in Constantinople cost 320,000 pounds of gold when it was constructed between 532 and 537. Even if that cost were exaggerated by a factor of ten, it was still a staggering amount of money for the Roman Empire to spend, as it was waging war simultaneously in Italy and Persia. (source)

Between 1828 and 1845, Russia coined money made of platinum. (source)

The word "exchequer" dates from the reign of King Henry I of England (reigned 1100–1135). Inspired by the abacus, it was a piece of chequered cloth upon which counters or cash were placed for counting by sheriffs and other officials. Eventually, the person in charge became the chancellor of the exchequer, and the issue of money became known as a cheque. (source)

The Yap islanders in the South Pacific sometimes use stone rings, up to 12 feet in diameter and weighing up to four tons, as money. (source)

The word "posh" dates from the 19th century, as a slang term for a low-denomination coin. For some unknown reason, later on in the century, it came to connote a dandy, and from there evolved to mean stylish. The modern sense of the word was first used in Punch magazine on September 25, 1918. There is an urban legend that the word "posh" is an acronym for "port out, starboard home" on tickets to India that would entitle the bearers to avoid the hot sun going both out and back, but there is no contemporary evidence to support this derivation. (source)

In 1266, Henry III of England decreed that "an English penny, called a sterling, round and without any clippings, shall weigh 32 wheatcorns in the middle of the ear. Twenty pence do make an ounce, and 12 ounces a pound". The English kings used troy (named for the French town Troyes) weight for currency measurements, and in 1527 it became the legal standard for minting coins.

Ancient Greek coin depicting a swastika.

The swastika was not invented by the Nazis. It is one of humanity's oldest symbols and probably originated in Asia. The ancient Aryans of India drew swastikas to represent the sun's motion across the sky, and this solar wheel became an emblem of the sun's goodness and regenerative power. In ancient Sanskrit, swastika means "conducive to well-being". Swastikas have also been found on Persian carpets, on representations of the Buddha, on ancient Greek and Cretan coins, and in the Roman catacombs, where it was used as a disguise for a cross by early Christians who sought to avoid persecution. (source)

In 1865, William E. Brockway printed a counterfeit $100 bill so perfect that the Treasury Department's only recourse was to withdraw all authentic $100 bills from circulation. (source)

During the U.S. Civil War, a shortage of coins prompted the U.S. government to print bills in denominations of 5¢, 10¢, 25¢, and 50¢. (source)