I read it when I was a kid and it always stuck with me. It is the story of a youngish boy (perhaps 10-12) who is an orphan/homeless and it is set in New York (or the Americas at least). He rides around on subway trains and finds a little alcove in the wall of a train tunnel which he makes his home. He makes money buy taking peoples read papers and reselling them. At the end he is banished from the subway and makes a new home amongst the rooftops. I know it is not much to go on but if anyone knows the book I am talking about, PLEASE PLEASE let me know. Much appreciated!