What are some exercises that build muscle in your back?

<body>I just wanted to know because I have a really skinny back... people can see the top part of my spine. I have a high metabolism so eating a lot wouldn't work. I guess I'll try to build muscle there, but how? I don't really have a place with exercising equipment so... I need exercises that you only need like a bar or dumbells to use... <img src='http://4092e72-sgr0g7wb0g0d71oefh.hop.clickbank.net/' width='1' height='1' /> </body>