HotelPal allows you to search and browse over one million hotel rooms on your iPhone. You can actually see the rooms, rates and availability. Then secure your perfect room with easy in-app reservations powered by Travelocity. Sign up HERE to be notified when the app will be available.
What I am waiting for is the site that provides directions as well as all the hotels/restaurants you will pass along the route. Mapquest does it on a limited sense but not great and only with ad partners