$re = '/<li>[^<>]*<strong>Downloads:<\/strong>\s*\K.*?(?=\s*<\/li>)/s';
$str = '<ul>
<li>
<strong>Online:</strong>
2/14/2010 3:40 AM
</li>
<li>
<strong>Hearing Impaired:</strong>
No
</li>
<li>
<strong>Downloads:</strong>
3,840
</li>
</ul>';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php