In Drupal 6, it was easy to insert a block into a template with the following code:
$block = module_invoke(\'views\', \'block\', \'view\', \'block_name\');
print
This worked for my Drupal 7 , URL: admin/structure/block/manage/addthis/addthis_block/configure NOTE:delta and module name present in the url itself
$addblock = module_invoke('addthis','block_view','addthis_block');
print render($addblock['content']);
More information can be found on http://technarco.com/drupal/insert-block-node-or-template-drupal-7