Hilton just announced their new promotion for the first quarter of 2013. Registration is already open. You may choose between either double points or double miles for stays between January 7 and March 31, 2013.
Once you have selected either option, you are automatically registered and cannot change your selection anymore. To take advantage of this offer you have to register before check-out of your first stay during the „Promotion Period“.
As is often the case with Hilton promotions, the list of non-participating hotels is very large. I had just completed two bookings of one-night stays right before I received the e-mail. Luckily, both hotels are not in this list.
Registration link: HHonors.com/Double