WE HEART PARTYING: The third annual iHeartRadio Ultimate Pool Party, presented by VISIT Florida at the Fontainebleau Miami Beach hotel splashed down this weekend. The two-day fete, hosted by Nick Cannon, featured performances from Iggy Azalea and Ariana Grande (seen above), Tiesto, Lil Jon, Neon Trees, Jennifer Lopez, RCA's buzzing Magic! and underground experimental hip-hop artist Zebra Katz. Highlights included Tyler Glenn's (of Neon Trees) cover of Tiesto's "Red Lights," DJ Steve Aoki's unexpected performance with Lil Jon for "Turbulence," Matthew Koma joining Tiesto for "Wasted" and Cannon's tease of his new single "America" f/Pitbull. Snowboarder-turned-musician Shaun White, Jake Miller, Katie Tiz, Josh Peck and J Lo's mother, who was dancing up a storm, were spotted in the crowd. The show will air nationally on The CW on Wed 7/9 at 8-9:30 pm ET/PT. In a related story, Bob Pittman's jet has its own pool. (6/30a)