Has anyone used the site BackBid.com? There was an article in the travel section of the paper today and it seems like an interesting idea. It's like Priceline in reverse. You basically submit your (cancellable) hotel booking on the site and other hotels "bid" and try to give you a lower rate.
You find out the hotel name, room type, other benefits (free parking or breakfast) with the bid.
I might try it for my next hotel stay in San Francisco in September but its going to be very busy there then so many hotels might be sold out so I might have to wait until I stay somewhere else.