It's fair to say millions of people have unwittingly laid hands on Diggs's work, an audience few artists can match. ''It's kind of like graffiti, but in a small, private way," says Diggs. ''I just love that there are people out there I've never met who are thinking about ways money has hurt them."
The money-stamping project is just one of her many works of public art, a genre-bending form that defies artistic conventions. It's not the kind of art that hangs in museums and galleries. It's not the kind that makes Diggs any money, either. ''Sometimes the work takes a form that doesn't look like art at all," she says.
She has plastered buses in Boston with children's artwork. She has decorated milk cartons in New Jersey with a message about domestic violence. Her next project involves working with prisoners in Pennsylvania on developing products for people in cramped spaces.
Erin Donnelly, curator of the Lower Manhattan Cultural Council, said public artists such as Diggs are stretching the traditional boundaries of art. ''Her work draws a solid connection between art and everyday life in a meaningful way," said Donnelly, whose council awarded Diggs a five-month residency last summer.
Patricia Phillips, chairwoman of the art department at the State University of New York-New Paltz, said the money project is as artistic as any painting or sculpture.
''I think it's art because she is taking this very common and banal system of distribution and intervening, bringing another message into this currency," said Phillips, who wrote an essay on Diggs's work in a book called, ''But Is It Art?"
Diggs has traveled the country to pursue her craft. She collaborated with at-risk youths in Boston to decorate MBTA buses with billboards about the perils of street violence. In a neighborhood torn apart by gang warfare in Hartford, she initiated a dialogue between elderly women who were afraid to leave their homes and teens who also felt threatened by gang members. Their words were printed in a newspaper insert.
She helped homeless women in Chicago create banners with slogans challenging stereotypes about homelessness. They blanketed the buildings and streets of a crack-infested neighborhood.
