TripMojo.com is a hotel search engine with the ability to plot your results on a Google Map. The site itself has the feel of Google's search site. The search field just asks for the location and not multiple fields like an Expedia-like travel search. The anonymous poster that apparently "found" the site mentions that there are some international locations mixed in as well!
(It can only be a matter of time before every travel and hotel directory website has this feature integrated..)