Near field communication, or N.F.C., is being used at a variety of events including music festivals and trade shows. The system is most often activated with tags embedded in wristbands or badges, or with N.F.C.-enabled smartphones. Here are examples from seven events that have used the wireless communication technology for everything from collecting information from attendees to providing cashless payment systems.

At Mobile World Congress in Barcelona, Spain, in February, attendees could use their N.F.C.-enabled devices to access event information and download materials at kiosks, redeem food coupons at catering outlets, and participate in a treasure hunt. Organizers estimate 51,000 N.F.C. transactions were made during the four-day event. In addition, users could create an N.F.C. photo badge within the event’s mobile app, which expedited entry to convention facilities. Sponsor Incipio offered its Cashwrap N.F.C.-enabled cases for free so iPhone users also could participate.

Dell is using N.F.C. for the first time during its Dell Solutions Tour, which is taking place in 20 European cities through November. Zappit is printing plastic N.F.C. badges on site at each event. After attendees visit the product displays, they tap their badges on a kiosk to launch a survey. To encourage participation, the system is linked to a prize drawing.

Exhibitors participating in the Dell Solutions Tour, currently taking place in cities around Europe, are using Zappit’s N.F.C.-reader app. By tapping the device to an attendee’s N.F.C.-enabled badge, the app retrieves that person’s contact information and provides a place for the exhibitor to add notes.

At the International Broadcasting Convention in Amsterdam in September, organizers created a wall displaying magazines from 30 sponsoring publishers. Below each magazine was a Btag—a self-contained N.F.C. hot spot provided by ITN International. Attendees simply tapped their N.F.C.-enabled badges to the Btag to receive a digital copy of the magazine, eliminating the need for publishers to provide bins of printed copies.

At the end of each day, attendees received an email that included links to each publication they had “touched” on the media wall.

At the Food Network South Beach Wine & Food Festival in February, sponsor Esurance provided N.F.C.-enabled wristbands each night in the North Venue. Guests tapped the bands on tablet computers displayed next to each chef and sponsor station to save information about food items, recipes, and other perks in an online account. ClearHart Digital, which created the wristbands, calls the system a “digital memory bank.”

At the International C.E.S. in January, ITN International created and distributed 160,000 N.F.C.-enabled badges at more than two dozen sites, including at the airport and designated hotels. Guests used the badges to check in to educational sessions and also to provide contact information to exhibitors that were using ITN’s app.

In late 2013, Intellitix began using its IntelliPay cashless payment bands at festivals around Europe, including the Majales festivals in the Czech Republic. Users create an online profile to link the band with a credit card or PayPal and then could tap it on a reader to purchase food, merchandise, and other items around the venue. The company will use the system at two upcoming events in North America: Mysteryland USA in New York later this month and Digital Dreams in Toronto in June.

The 450 attendees at Web à Québec in March wore N.F.C.-enabled bracelets from Connect & Go, which could be used for Facebook check-ins and photo sharing from six sponsored kiosks throughout the event.