Travel Web site Orbitz is starting to show Mac users different, and sometimes costlier, travel options than Windows visitors see, Orbitz executives confirmed. Tracking people\'s online activities, Orbitz has found Mac computer users spend as much as 30 percent more per night on hotels, and has begun showing different hotel offers to Mac and PC visitors. Orbitz executives said the company isn\'t showing the same room to different users at different prices, but rather is showing different offers, having determined Mac users are 40 percent more likely to book a four- or five-star hotel than PC users. \"We had the intuition, and we were able to confirm it based on the data,\" Orbitz Chief Technology Officer Roger Liew told The Wall Street Journal. Orbitz said it first confirmed Mac users\' preferences in October and has begun including them among the many factors involved in determining search results. Orbitz chief scientist Wai Gen Yee said the travel site may start to examine if Mac users also have identifiable preferences in car rentals and flight bookings. \"It would be nice to say they book more Porsches, but at this point we\'re only looking at hotels,\" Yee said.