I can thoroughly recommend traveling via tram if you visit Lisbon. It is totally tram-tastic fun 🙂
First off make sure you choose an older tram, the new trams are nice and have air conditioning but the older trams have more fun routes. For instance the number 18 to Belem has to travel up a series of steep inclines (we caught it upto the palace). as it traverses the narrow streets and sharp turns pedastrians scatter and motorists risk life and fender to avoid the great metal monsters.
On one incline we passed a car that had parked a litle too close to the tramlines. The tram driver didn't pause, didn't sound a horn, didn't do anything but slow slightly so as not to derail before easing past to the accompanying squeal of metal as side of car met large iron bumper. There was more than one smiling face as locals and tourists alike looked out if the window to admire the artistry.
Grab a travel card from a local kiosk for unlimited travel on the many trams, buses and metros.