check if we have a node page or a taxonomy page in a custom block content function
<?php
  //get object
  $obj = menu_get_object('node',1);
  if (isset($obj)){
  	// it's a node page
  } else {
  	// it's a taxonomy page
  	$obj = menu_get_object('taxonomy_term',2);
  }
  dpm($obj);