In recent years I've noticed an increase in the number of Wheat Pennies I find in circulation. Just yesterday I found a Wheat Penny lying wheat side up (tails) on the street. Wheat Pennies were minted from 1909-1958 and are said to be worth from .03 cents to several hundred Dollars each for circulated coins-- the only variety you'll find in your spare change.
Uncirculated Wheat Pennies can be worth thousands of Dollars but you'll not find them just laying about somewhere.
I've also found a few Indian Head Pennies (1859-1909) Mercury Dimes (1916 -1945) and silver Washington Quarters minted prior to 1965. These quarters currently trade at over $6 each with some going to several hundred Dollars in value.
Prior to the economy going to hell I almost never found such coins. Now it's as if it's an almost regular experience for myself and others. I also find lots of foreign coins minted of pure silver and gold given to me at cash registers for pennies, nickles, dimes and quarters. Most people seem to want to rid themselves of them probably because they feel as if someone else stuck them with these odd coins and they fear they might be worthless.
The increase in the old US coinage in circulation is probably due to desperate people raiding small private collections of coins just to buy the things they need to get by. Once they're back into circulation there's no telling how many hands they cross before someone like me recognizes them and stashes them away.
Such is the case with most things of value. If they're not new and shiny, most people are unable to recognize the value in them. Cities like Greensboro focus on downtowns and shiny new performing arts centers while forgetting about the hidden values circulated among the outlying communities. And in doing so those communities become neglected, tossed to the ground and lost in the hope that someone will someday find them lying tails up and rescue them from being swallowed up by the earth. Sadly, unlike the Wheat Penny I found yesterday, most old coins and most forgotten communities are never found.