Based in Chicago, Orbitz is backed by five US airlines: American, Continental, Delta, Northwest and United.

A visit to their respective websites reveals similar approaches. Orbitz benefits from its English-speaking domestic market, and the visitor is immediately welcomed by a travel portal that means business. Sooner or later, the emergence of the large Hispanic minority in the US may push Orbitz toward Opodo's situation.

Both Orbitz and Opodo extensively promote deals on their front pages, and offer tabs as navigation menus, to direct the visitor to book Flights, Hotels, Cars, etc. Orbitz’s use of white with light blue accents gives the site a clean look. Opodo is dominated by a wide horizontal burgundy strip that occupies the top of its site. It is rather massive, if not heavy, but it helps reinforce the brand color, which is also the color of the European passport.

A click on Cars, and Orbitz immediately asks for your itinerary before submitting an offer, whereas Opodo first asks the visitor to choose between Holiday Autos or Hertz. Although Opodo may have good reasons to do so, Orbitz's design provides the instant gratification that is so important on the ‘net. After entering an itinerary, Orbitz offers a comparison table formatted for the visitor, with (in our review) a selection of cars from Alamo, Dollar, Hertz and Avis.

It should be noted that both Opodo and Orbitz have done a remarkable job at integrating their systems with their vendors such as Holiday Autos and Hertz. Rather than losing contact with the visitor, both Opodo and Orbitz manage the branded interface while gathering information on the visitor's itinerary. From a branding and customer experience viewpoint, this is better than many travel sites that simply link to the vendor's website.

In this contest, there is no clear winner, and certainly no knock out to brag about. However, Orbitz -- which has more experience than its younger sibling -- demonstrates in the nuances that it has the upper hand.