We just got back from our Spain/Portugal trip and I need to tell you about one of the tours we took. It's called GoCars and they have them in a bunch of cities but we did ours in Lisbon. It was a blast!!! After you get over the hair net and helmet you'll have so much fun!
I must warn you, though, be prepared for a bumpy ride! The streets of Lisbon are, for the most part, cobblestone. Also make sure you take someone with you that work a camera quickly. There isn't always a place to pull over to snap a photo. Here's some of what my passenger/photographer got...
If you are in Lisbon or even another one of the cities that has Go Cars I would highly recommend that you do it! It's a really unique way to do some sightseeing and I guarantee you you won't ever forget the experience.
