You should also consider taking a look at Priceline's Name Your Own Price option. I know that this may not be an option for most but I have used it several times and have gotten some incredible deals (usually 60% or better off of some really nice hotels). I think it is daunting for most because they don't know how it works or where to begin. I have found several sites that can help you with the research but my new favorite is
TripDucky.com. They help you figure out at what price level you should start as well as showing you what others have won in the area that you are looking to stay. They also have some really good tutorials on how Priceline works as well as how to go about researching everything. Anyway, just wanted to throw out another resource for you to check out...