ResearchWhat is Exonumia?
Exonumia is related to coin collecting, but is instead devoted to non-currency items: tokens, medallions, commemorative pieces, and such. Many coin collectors run a side gallery of exonumistic items that they find interesting, and many coin-shooters and treasure hunters run across items in this category as well.
Casino chips are becoming quite popular. Many coin shows have a casino chip dealer or two, and there are even catalogs that sort and list them just like coin books. Because chips are the same as cash on the casino floor, casinos go to as much trouble to mint and authenticate these chips as the US mint does with our currency.
Tokens can range from video game arcade tokens to historic pieces. Tokens have been issued traditionally by businesses as a form of advertising, or for convenience. There are bus tokens, plantation tokens, bakery tokens - nearly any business has issued a token at one time or another somewhere. These will sometimes have the legend "good in trade", and what it's good for can be anything from a loaf of bread to a haircut to a cigar to... well... see, I have one "cat house" token, circa 1880, from the "Poke of Gold Saloon" in Folsom, California. According to the details stamped on it, it entitles the bearer to a $3 "all-night-check" and says, rather plainly, that it is good to "screw 8 ladies, 2 squaws". I have no idea if that's either-or or in total. Tokens from businesses of all kinds are scattered throughout history, and you are as likely to find them while hunting with a metal detector as any other metal cash piece.
Nearly any tourist trap has a nearby machine you can use to turn a penny into a souvenir elongated token. Some people collect these, but a real coin collector is likely to look down on these as ruining a perfectly good penny.
Other historical tokens are unofficial coins struck for general public usage before the founding of the United States Mint, or coins struck as "scrip", which is any substitute for currency which is not quite legal tender. These range from the coinage temporarily minted by the Confederate States of America in 1861, many of which were produced under duress by people fearing later arrest by the Union, to the New York Brasher Doubloon of 1786 and '87, minted by Ephraim Brasher the Philadelphia goldsmith and jeweler, to the Alaskan "Bingles", minted and distributed during the early effort to colonize Alaska after it became Americanized.
Wooden nickels are just another form of scrip. In times in American history when minted currency was scarcer than the goods being produced and traded, scrip was issued on any old thing at hand, and wooden nickels were actually used in the Wild West. So the expression "Don't take any wooden nickels" actually has some basis in fact. Oh, speaking of expressions, how about "Queer as a three-dollar bill"? Well, I have had one, from Macon Georgia in 1863, issued by the bank there. It was in such ratty condition when I got it that it only cost $20, but could have paid a fortune in winning bar bets had I exploited that aspect. Paper scrip includes even fractional currency - paper notes for as little as five cents - but unfortunately, little to none of this survives to be found by treasure hunters.