Portuguese media seems fascinated by Obama's limousine, a sleek, armored car they've dubbed Cadillac One.
Newspapers and magazines have run photos and half-page graphics marveling at the vehicle, which also is known in Washington as "The Beast" because of its extra-thick doors and huge tires.
Noticias magazine called it a "bunker on wheels." Sabado, another magazine, calculated that the gas-guzzling Cadillac cost more than three times the Portuguese president's unarmored car.
Socrates, meanwhile, arrived at the NATO summit in an electric car after a short ride across the Atlantic port city from his office in the 19th-century Sao Bento palace.
A major theme of Socrates' government is the shift to renewable energy. The country has been a European pioneer in the development of solar and wind power, and is setting up a national network of charging stations for electric cars.
Obama's limo attracted outsize interest from local media during portions of his recent trip to Asia, as well.