Here is the list of participating hotels. The promotion runs January 6th to April 6th, 2009.
Participating hotels list.
I’ll try to scrounge up the rules. Here is the registration page.
Double Base Points at These Hilton Properties
Ink Bold® Business Card
Ink Plus® Business Card
Chase Sapphire Preferred®
Starwood Preferred Guest® Credit Card from American Express
Delta Gold SkyMiles Card 30,000 Miles
Premier Rewards Gold Card
Business Gold Rewards
Citi Hilton Reserve
