Just in case anyone likes filling up their credential with pretty stamps (carimbos/sellos), the Cervejaria Paco Real, in the Baixa (flat part of centro historico) has a very pretty one with a codfish. It's on the Rua da Conceiçao near the crossroads with the Rua da Prata. Easy to find and central. And they have good home made meals, especially pastries. Nothing high end, but very good. It was there I learned that the pastel de nata does not have to be hot to be delicious. Take that, Pasteis de Belem!
And while I'm thinking about that neighborhood, a good pre-caminho place to sleep for those who prefer something other than youth hostels but don't want to spend a lot of money, try the Pensao da Prata. On the Rua da Prata. Family run, clean, a few blocks from the Cathedral, where the first arrow is!