Heres a hack to the backoffice that adds a checkbox to the post list instead of delete buttons/links, so you can delete multiple posts at once.

I've sent a pm to blueyed to see if this can get added into the 1.7> releases.

It's made for 1.7 but will probz work for all versions although i havent tested, heres the mod:

NOTE: The changed parts are only in the '//balupton mod {' and '//balupton mod }' comments, everything else is to help you know where to stick the code.

Line 371 of 'admin/edit_actions.php':

case 'delete':
		/*
		 * --------------------------------------------------------------------
		 * DELETE a post from db
		 */
		$AdminUI->title = T_('Deleting post...');
		require( dirname(__FILE__) . '/_menutop.php' );
		
		//balupton mod {
		param( 'post', 'string' );
		if( empty($post) ) {
			echo "<div class=\"panelinfo\">\n";
			echo "<h3>Please select at least one post to delete.</h3>\n";
			echo "</div>";
			break;
		}
		
		if(substr($post,strlen($post)-1) == ',')
			$post = substr($post,0,strlen($post)-1);
			
		$posts = split(',',$post);
		
		for( $iPosts = 0; $iPosts < sizeof( $posts ); $iPosts++ ) {
		
			$post = $posts[$iPosts];
			
			// echo $post;
			if( ! ($edited_Item = & $ItemCache->get_by_ID( $post, false ) ) )
			{
				echo '<div class="panelinfo"><p class="error">'.( T_('Oops, no post with this ID!') ).'</p></div>';
				break;
			}
			$blog = $edited_Item->blog_ID;
			$location = 'b2browse.php?blog='.$blog.'&amp;filter=restore';
	
			// Check permission:
			$current_User->check_perm( 'blog_del_post', '', true, $blog );
	
	
			// DELETE POST FROM DB:
			echo "<div class=\"panelinfo\">\n";
			echo '<h3>', T_('Deleting post...'), "</h3>\n";
			$edited_Item->dbdelete();
			echo '<p>'.T_('Deleting Done...')."</p>\n";
			echo '<p>'.T_('No More Post #'.$post)."</p>\n";
			echo '</div>';
		
		}
		//balupton mod }

		break;

Around line 195 of 'admin/_browse_posts_list.inc.php':

	// Actions:
	echo '<td class="shrinkwrap">';
	// Display edit button if current user has the rights:
	$Item->edit_link( ' ', ' ', get_icon( 'edit' ), '#', '', $edit_item_url );

	// Display delete button if current user has the rights:
	
	// balupton mod {
	$canDelete = true;
	if( ! is_logged_in() ) 
		$canDelete =  false;
	if( ! $current_User->check_perm( 'blog_del_post', 'any', false, $Item->blog_ID ) )
	{ // User has right to delete this post
		$canDelete =  false;
	}
	
	if ( $canDelete ) {
	?>
	<input type="checkbox" name="DelCHK<?=$line_count?>" id="DelCHK<?=$line_count?>" value="<?=$Item->ID?>" />
	<?php if ( false )
	$Item->delete_link( ' ', ' ', get_icon( 'delete' ), '#', '', false, $delete_item_url );
	}
	// balupton mod }

	echo "</td>\n";

	echo '</tr>';
	$line_count++;
}
echo '</table>';

//balupton mod {
?>
<script language="javascript" type="text/javascript">
function DelCHKFunc() {
	//you owe balupton for this one
	var url = String("<?=$admin_url.'edit_actions.php?action=delete&post='?>");
	var posts = String("");
	for(var i = 0; i < <?=$line_count?>; i++)
		if( document.getElementById("DelCHK"+String(i)).checked == true )
			posts += document.getElementById("DelCHK"+String(i)).value+",";
	if( posts == "" )
		alert('You must select some posts to delete.');
	else
		document.location.href=url+posts;
}
</script>
<?php
$r = '';
$r .= '<input type="button" title="Delete Selected Posts" value="Delete" onclick="if ( confirm(\'';
$r .= TS_('You are about to delete selected posts!\\n\'Cancel\' to stop, \'OK\' to delete.');
$r .= '\') ) { DelCHKFunc(); }"';
if( !empty( $class ) ) $r .= ' class="'.$class.'"';
$r .= '/>';
echo $r;
//balupton mod }

Around line 109 in the same file as above:

echo '<th>'.T_('Actions')."</th>\n";
echo "</tr>\n";

//balupton mod {
global $current_User, $admin_url;
//balupton mod }

$line_count = 0;
while( $Item = $MainList->get_item() )
{

Works perfectly for me, tested and all, just need to be updated for translations but thats not my area.

Hope this helps, don't forget to credit me if u use it.

-balupton