Seven years ago, St. John started collecting used MetroCards, affixing stickers with his contact information to them to use as business cards for his company, HunterGatherer.

“People like it,” he said. “They usually ask if there's any money on it.”

St. John's cards reflect his firm's eye toward transforming and reusing the ordinary, as well as a wider and growing trend toward unorthodox business cards.

Even with the digital age firmly upon us, the humble paper business card maintains relevant as a marketing and networking tool, experts say. What's changing is how the cards look and who's using them.

Soccer moms hand out cards and scribble play dates for their kids on the back. Entrepreneurs ditch the standard size in favor of thinner, sleeker cards no larger than a pack of gum. Teenagers pass out “social networking cards” at parties with their name and Facebook or MySpace address.

“Leveraging the digital age for the physical side is very big,” said James Heckman, chief strategy officer at Zazzle, a Web site that ships customized business cards and other products to customers within 24 hours. “At the end of the day, we still have to meet each other. We have to face each other.”

Heckman uses the company's popular “skinny cards,” which are half the standard size and come with a Pez-like dispenser.

“They're just so much easier to carry and I get such a reaction,” he said.

Zazzle's cards are inexpensive, fast and available in smaller quantities. Such features are important to entrepreneurs and small-business owners, who don't want to wait a week and pay hundreds of dollars for the industry-standard minimum of 250 cards.

Staples Inc. now offers a service that allows users to design, proof and print business cards in about 30 minutes. One offer is for 100 full-color cards for $3.99.

“We're seeing ghost hunters to scuba dive shops to CEOs of small startup companies,” said Rob Schlacter, Staples' vice president of business services.

Another growing demographic are “slashers,” entrepreneurs with cards tailored to several different businesses or skill sets, he said. Think engineer/animator/basketweaver.

Schlacter's kids have used the service to make cards with their Facebook and college e-mail addresses to give out at parties.

“Rather than write your name on a napkin, they'll hand them out,” he said.

Those cards just don't cut it, however, in professional settings, according to career coach Mary Crane. She often tells college graduates that a business card reflects a job applicant's credibility.

People in creative professions can get away with more unusual sizes, designs or job titles, but not at the expense of clearly presented information, said Gene Fairbrother, lead small business consultant at the National Association for the Self-Employed.

“The key marketing component to a business card is to get people to keep it,” he said. “Don't get cute with it. Don't try to communicate too much information on it.”

Jeff Fisher, a graphic designer in Portland, Ore., has endured grumblings about his large, square business card not fitting into traditional card holders. Modeled after a Monopoly card with a train image that reads “Jeff Fisher Logomotives,” the card's distinctiveness outweighs any inconvenience, he said.