If you have dynamic pages, another thing you can do is log all the referring addresses, for example in PHP:
Code:
<?php
$rf = $_SERVER['HTTP_REFERER'];
$logfile = '/mylogdirectory/myreflogfile';
if ( $handle = @fopen($logfile, 'a') )
{
fwrite($handle, $rf . "\n");
fclose($handle);
}
?>