Six of the world's largest hotel companies have collaborated to create a Web site that allows travelers to search listings and then book rooms directly on hotel sites, effectively cutting out middlemen like Expedia. The site, Roomkey.com, is owned by Choice Hotels International; Hilton Worldwide; Hyatt Hotels Corporation; InterContinentalHotels Group; Marriott International; and Wyndham Hotel Group, part of the Wyndham Worldwide Corporation....