One thing that I would add to your suggestion to check the web sites is to sign the guest books that many of the sites have. By signing and filling out their form with your email address they will send you frequent offers for discounted room rates. Some times they may not look all that exciting, price wise, but when you add in some of the coupons that they offer as well there are some good deals.

Before a trip to LV a couple years ago I signed all the guestbooks that were available and I now get offers from everyone from Hilton to Mandalay Bay. Sometimes an offer every week from each.