Poor Justin Bieber. While his fellow musicians Drake and Timbaland were throwing down until dawn with LeBron James and the other members of the Miami Heat at the team's victory bash in South Beach, E! News has learned exclusively that the teen heartthrob was left out in the cold. Madonna is one of the first celebs to jump into the Instagram video craze, and for her first post she's showing her fans that she can still "get into the grove." The 54-year-old pop icon, wearing workout gear and fingerless gloves, is seen dancing her little toned toosh off in the clip. Madge repeats the phrase "booty pop" as she does just that, and rounds out the video by declaring she is, "addicted to sweat." Kim Kardashian and Kanye West named their daughter North; where does that moniker rank on the all-time list?