Body language is important when giving a presentation. Here is some sites to read more about this topic.
http://www.positivityblog.com/index.php/2006/10/27/18-ways-to-improve-your-body-language/
http://www.wikihow.com/Communicate-With-Body-Language
http://money.cnn.com/2000/05/03/career/q_body_language/
http://travel.ca.msn.com/international/photogallery.aspx?cp-documentid=22585990&page=1