<?php
$numposts = $wpdb->get_var("SELECT COUNT(*) FROM $wpdb->posts WHERE post_status = 'publish'");
if (0 < $numposts) $numposts = number_format($numposts); 

$numcomms = $wpdb->get_var("SELECT COUNT(*) FROM $wpdb->comments WHERE comment_approved = '1'");
if (0 < $numcomms) $numcomms = number_format($numcomms);
?>
There are currently <?php echo $numposts ?> posts and <?php echo $numcomms ?> comments in this weblog. Enjoy!