Back in May I posted about Starwood offering 250 points for checking in at one of their hotels with Foursquare in conjunction with a confirmed reservation through July 31. Well, Starwood has expanded this offer to include checking in with Facebook as well. Through July 31 you can earn 250 points by checking in through Facebook in conjunction with a confirmed reservation.
You can check-in through both Foursquare and Facebook for each reservation, for a total of 500 points per stay.
In order to qualify you have to sign-in and link your Starwood account with your Facebook and/or Foursquare account.