Starwood is awarding 200 free weekend nights at its hotels, which spam nearly 100 countries, through an international social media scavenger hunt that will lead travelers to properties across the globe. The 10-day Starwood Preferred Guest (SPG) Passport to Free Weekends contest started on May 12 and offers clues on Facebook and Twitter. When the participant determines the identity of the designated hotel, they will approach the front desk to claim their prize. The first 10 winners will get their "passport" photo taken, which will then be posted on SPG’s Facebook and Twitter pages.