By Leah Abrahams
Mar 02, 2012 @ 1:00 pm
Michael Buckner/Getty Images

Kourtney Kardashian and Ashlee Simpson headed to Hollywood to kick off Caesars Entertainment's "Escape to Total Rewards," a series of simultaneous concert events in four cities. "Im Escaping w/ @Total Rewards Lil Wayne & @CeeLoGreen tonite @ Hollywood & Highland!Kardashian tweeted. Click through the gallery to see Jennifer Lopez, Salma Hayek and more stars at last night's hottest events.