I have found perhaps a half-dozen punched coins in various projects in
Virginia. In each case there is a pretty strong association with
African-American occupants. The practice remains current in many parts of
the South--I have been told that many women wear small single coins on
anklets in the Deep South, and when I brought this up with a black female
friend she hiked her jeans and showed me hers--coin, that is.
 
I have read, but cannot find the ref at present, that the coin is a
talisman that wards off the "evil eye" in some traditional
interpretations, and that most people today think of it basically as a
good-luck charm. But I have also heard or read of a more specific
function--that some African-American women used coins on anklets to as a
form of magic to attract a man and keep him faithful.
 
It is also possible that, as is common practice with both coincs and cowry
money in W. Africa, the pierced coins represent a form of portable
personal wealth and tokens of prestige. In that sense, their function is
quite the same as the traditional use of precious jewelry--that is, as a
form of financial security owned and controlled by a woman relatively
independently of any man.
 
Dan Mouer
http://www.freedomnet.com/~dmouer/homepage.htm