Well, I'm impressed with the "people shots", they are very good storytelling images.
The image of the man with a beard is quite unique. It makes me wonder why his hands are spread, or what he might be trying to say. You've cropped it pretty tight - I might have included a bit more of his legs - this is sometimes called a "three-quarter shot."
I also like your use of depth of field, with the subject sharp and background out of focus. This gives the viewer fewer distractions, and more attention to your subject.
I also feel that you nailed the exposure. Many times this kind of shot is over-compensated for bright elements in the background, leaving the subject under-exposed.
The bridge shot is a very pleasant snapshot, but has a number of problems. Contrast is very flat, and overall the image is quite cluttered. At the least, I would crop the foreground, as the water doesn't really add much to the impact.
The image "Porto" is very good - the two silhouetted figures, and their angled shadows, are striking, to say the least. Some might say you cropped too close to their heads, but I think the crop creates some interesting energy and tension in composition. It works.
David SaffirGuruShots Photo Critique