During the day of this wonderful scale I first took the Metro to Cais do Sodré and I got to see the Ponte 25 de Abril (25 of April Bridge, 4th photo) which apparently is called the "twin sister" of the Golden Gate. In the photo you don't appreciate it, but live you can see why. It's massive, beautiful and red; smaller though.
Afterwards took the Metro to Avenida Liberdade, Lisbon's main boulevard where all the high-end shops are. I walked around a little and had an early lunch, shrimp soup and octopus salad. Yumm. Then, back to the airport straight to an 8 hours flight. Not fun.
Someday I want to go back to Lisbon with more than 24 hours to get to know it better... and eat more!
PS. I'm reading a really nice book, that is not on the list of Uni that I should be reading right now, and it's from 1979, but it's so interesting that I haven't been able to stop. It's called The Third Wave by Alvin Toffler. Have a look. It's worth it.