During Victorian era, leaving your calling card when visiting a friend or attending a party is the proper etiquette.

Fast forward a couple of hundred years, this quaint practice is coming back into fashion, but instead of "calling" cards, people are handing out their "calling-and-emailing-and-AIMing-andTwittering cards."

For a flagging stationery industry, calling cards--essentially nonbusiness business cards--have brought a welcome dose of energy. Some are teenier than standard business cards, others much bigger, and many come in bright colors that seem anything but stodgy. Among the buyers: playdate-seeking parents eager for a sane way to exchange contact info, retirees who miss having business cards to hand out (Memphis stationer Baylor Stovall calls them "cruise-ship customers") and itinerant young professionals whose cell phones and e-mail addresses are their most reliable locators.

Link - Thanks Michelle Shildkret!