We've also had good luck with Hotwire.com, as long as we stick with 3-1/2 Stars and up. We got a room at the Capitol Hilton for $99 but that was a few years ago.
One time I picked a 2-1/2 or 3-Star hotel near an airport for overnight and got more like a 1/2 Star, so the small price difference didn't work out.
