As found here:

http://codex.wordpress.org/Function_Reference/add_meta_box

/**
 * Calls the class on the post edit screen
 */
function call_someClass() 
{
    return new someClass();
}
if ( is_admin() )
    add_action( \'load-post.php\', \'call_someClass\' );

/** 
 * The Class
 */
class someClass
{
    const LANG = \'some_textdomain\';

    public function __construct()
    {
        add_action( \'add_meta_boxes\', array( &$this, \'add_some_meta_box\' ) );
    }

    /**
     * Adds the meta box container
     */
    public function add_some_meta_box()
    {
        add_meta_box( 
             \'some_meta_box_name\'
            ,__( \'Some Meta Box Headline\', self::LANG )
            ,array( &$this, \'render_meta_box_content\' )
            ,\'post\' 
            ,\'advanced\'
            ,\'high\'
        );
    }


    /**
     * Render Meta Box content
     */
    public function render_meta_box_content() 
    {
        ?>
        <div class=\'mydiv\'>
          <img src=\'someImage.png\' alt=\'someImage\'/>
          <script type=\'text/javascript\'>alert(\'hello world!\');</script>
        </div>
        <?php

    }
}