I've got to agree with Rebecca, most look a bit soft. I like the second one, but his eyes are definitely not what I'd call sharp... but I don't think it hurts the composition. I like the last one, but agree he should have the rest of his chin, and the sharpest part of that pic is his hair. The texture of his skin makes for a very dramatic image and would look excellent if it was all in sharp focus. Great pics though. I've often played around with the idea of walking around some parts of the city where homeless folk hang out... but I'm not sure how they'd feel about me snapping pics of them.