NEW YORK — New York City is getting ready for an old-fashioned Easter egg hunt with a 21st-century twist: The public will hunt for the eggs as part of an interactive contest using a smartphone app. Nearly 275 egg sculptures will be hidden around the city April 1-17 as part of The Faberge Big Egg Hunt. The eggs are about 2 1/2 feet tall (or about 3/4 meter) and were created by famous artists and designers like Tommy Hilfiger and Jeff Koons. A free downloadable smartphone application will allow the public to check in each time an egg is found. The eggs' locations will remain secret until 10 people use the app to check in at an egg. At that point its location will appear on an interactive map, becoming public. Participants will be eligible for prizes. Each egg is unique. In addition to Hilfiger and Koons, egg designers include architect Zaha Hadid, “Where's Waldo” creator Martin Handford, artist Julian Schnabel, Lego brick artist Nathan Sawaya and fashion designers Carolina Herrera and Ralph Lauren. From April 18-25, all the eggs will be gathered for a free exhibit at Rockefeller Center. They'll then be auctioned off by Sotheby's and the online auctioneer Paddle8 to benefit Elephant Family, a conservation organization, and Studio in a School, a program that brings visual arts to underserved New York City kids. Twenty-four of the eggs were made by students participating in Studio in a School programs. — APb