I am writing a wordpress plugin and want to add a meta_box for all types of posts ('page', 'post', 'custom_post_type'). By referring the wordpress <a href="http://codex.wordpress.org/Function_Reference/add_meta_box" rel="nofollow">add_meta_box()</a> I found it accepts only single type of post. Does anybody know how to do what I want? Thanks.