PointsHound is offering double miles/loyalty points for all hotel bookings that are made by August 31, 2013. The stay dates can be far out to the future.
PointsHound is basically a hotel reservation portal that rebates part of their travel agent commission back to you in form of airline miles/loyalty points.
The number of miles that you earn from your reservation is shown during the booking process. You can access PointsHound’s website here. You will get 250 bonus miles for your first booking.
I have yet to use their services, as I usually get a better deal by booking directly with the hotel and getting my hotel status related points and benefits in the process or book via one of the OTA’s (online travel agents) by using a coupon + getting some cash back.