Nickelodeon usually would want you to sit and watch its Saturday afternoon lineup of SpongeBob SquarePants, ChalkZone, Hey Arnold, As Told By Ginger and CatDog. But Saturday the network will go off the air from noon to 3 p.m. to get kids off the couch and outside playing during its Worldwide Day of Play. And as an added incentive for local kids, the network has planned a game day and family festival from 10 a.m. to 2 p.m. at Curtis Hixon Park in Tampa. Registration begins at 10, with the activities beginning at 11. Kids and parents who want to participate can preregister online at the Boys and Girls Clubs Web site: www.bgctampa.org. Activities include cork ball, stationary bike races, a soccer-goal kick and a live show with the Nickelodeon trademark "sliming." Once the network resumes broadcasting at 3, events in Tampa and four other cities will be featured in video updates. After all that activity, you should be rewarded. So at 6, Nickelodeon will air live segments from Worldwide Day of Play events at Nickelodeon's Nick on Sunset Studios hosted by Hilary Duff and Romeo. With events planned throughout the country and around the world, it will be the biggest play date ever.