US citizen looking to relocate to Lisbon or Porto

my advice would be to GO VISIT before you make plans to move somewhere! It's very different to live somewhere than just look at pictures and videos. Do you speak Portuguese? How do you plan to be a legal resident (what kind of visa, what kind of income do you have, do you have another citizenship?)

Quite a few of us (US citizens) have successfully obtained residency visas, and subsequently residency permits to live in Portugal, so yes it's doable  :-)    There are no restrictions regarding renting apartments.  Finding a job?  Very slim chance.

thanks all for your replays!... I'm a US citizen, I was born in Cuba, but migrated to US very young. Right now I'm 44 years old, and I have about 900+ $ monthly income. I work most of my life in Information Technology / Programming. I really don't know how difficult would be to find job in this industry, but I guess they would give priority to locals first. Also, how difficult is to start a small IT Consulting business? Would living on 900 bucks a month enough in Portugal? I'm aware that the Euro is more than the dollar...
Again thanks for advise

Would love to be more helpful, but you have some difficult personal questions.  Cost of living depends on your lifestyle.  When you visit here, if you even like it, you'll get a better idea of where you'd like to live and the rents, whether you'll need a car, etc.  I hate to be negative about finding a job, but not only is the economy weak, but I'm assuming you don't speak Portuguese, plus IT is a very youthful field and it is not easy for anyone over 40 to be hired in any field.  As far as starting a business, the entrepreneurial spirit is alive and well here, but you'll have to assess your particular situation for yourself.  Your first steps, as suggested above, would be to visit, and also to research whether you may qualify for a residency visa.  Good luck!