In China you often see a man with his arm around the shoulder of his male companion, or two guys walking along holding hands. It means nothing sexulal and nobody takes it that way.
In our culture, male/male hugs (and butt pats!) are accepted in sports, but can be suspect in other contexts.
I have gotten more demonstrably affectionate as I have grown older and other people's perceptions of my masculinity isn't something I feel compelled to worry about.
My friends (male and female) have started to drop the body with alarming frequency, so I want to be sure the ones I have left know that I love and cherish them. I frequently hug and sometimes give my best male friends a brotherly peck on the cheek.