The chart-topping singer hits the stage for a good cause in Las Vegas. Plus: Usher, Katie Holmes, Lauren Conrad and more

BADA-BLING

It's a bling-fest! R&B singer Ne-Yo and LL Cool J team up Wednesday at The Kress club in Hollywood, where they both performed sets during an invitation-only Hennessy-sponsored concert series. The duo has also collaborated in the studio for the remix of Ne-Yo's song "So Sick."