Finding the best accommodations for the money, though, can be difficult, not just because hotels will often shield their nicer rooms from the bargain Web sites. Adding to the challenge is the fact that online travel agencies and hotel merchants have generally been slower to focus their attention on improving the hotel-searching features of their Web sites, for a variety of reasons.

Now, though, online travel agencies like Expedia and hotel booking sites like Hotels.com are making broad improvements. Whether or not those changes were spawned by the debut in June of a potentially formidable competitor called Travelweb (www.travelweb.com ), the traveler benefits.

Travelweb takes a page from the playbook of Orbitz, the popular online travel agency that was founded by a consortium of airlines. The owners of Travelweb include Hilton, Hyatt, Marriott and Starwood (which includes the Sheraton, Westin and W brands), among others chains that for years watched as their local affiliates advertised cheap rates on independent hotel Web sites in exchange for virtually guaranteed bookings.

The cheaper bookings both undermined the fiscal health of the hotel chains and diminished their premium-brand stature with consumers, analysts said, while also leaving customers open to sometimes unpleasant experiences. Some customers who prepay for a cheap hotel room on Hotels.com, Expedia or other Web sites find that when they show up at the hotel, the Web site never actually secured a reservation, said Henry Harteveldt, a travel analyst with the technology consulting firm Forrester Research.

Finding the best accommodations for the money, though, can be difficult, not just because hotels will often shield their nicer rooms from the bargain Web sites. Adding to the challenge is the fact that online travel agencies and hotel merchants have generally been slower to focus their attention on improving the hotel-searching features of their Web sites, for a variety of reasons.

Now, though, online travel agencies like Expedia and hotel booking sites like Hotels.com are making broad improvements. Whether or not those changes were spawned by the debut in June of a potentially formidable competitor called Travelweb (www.travelweb.com ), the traveler benefits.

Travelweb takes a page from the playbook of Orbitz, the popular online travel agency that was founded by a consortium of airlines. The owners of Travelweb include Hilton, Hyatt, Marriott and Starwood (which includes the Sheraton, Westin and W brands), among others chains that for years watched as their local affiliates advertised cheap rates on independent hotel Web sites in exchange for virtually guaranteed bookings.

The cheaper bookings both undermined the fiscal health of the hotel chains and diminished their premium-brand stature with consumers, analysts said, while also leaving customers open to sometimes unpleasant experiences. Some customers who prepay for a cheap hotel room on Hotels.com, Expedia or other Web sites find that when they show up at the hotel, the Web site never actually secured a reservation, said Henry Harteveldt, a travel analyst with the technology consulting firm Forrester Research.