내공이 부족해서 preg_match_all 은 못하겠네요.

<?
$s =<<<HTMLCODE
<a target=_blank href='http://www.naver.com'>네이버</a>
<area shape="RECT" target="_blank" coords="10,10,135,60" href="http://www.daum.net" />
HTMLCODE;

preg_match("/(\<a[^\>]*\>)/i", $s, $match1);
preg_match("/href\=[\"\']?([^\"\'\s\>]+)/i", $match1[1], $match2);
preg_match("/\<a[^\>]*\>(.*)\<\/a/i", $s, $match3);
?>
<textarea rows=10 cols=100><?print_r($match1)?></textarea>
<textarea rows=10 cols=100><?print_r($match2)?></textarea>
<textarea rows=10 cols=100><?print_r($match3)?></textarea>

preg_match_all 로 만들어 봤습니다.

preg_match_all("/(<a[^>]*href=[\"']?([^>\"'\s]+)[\"']?[^>]*>)([^<]*)/i", $s, $out1);

echo "<xmp>";
print_r($out1);
echo "</xmp>";

Array
(
[0] => Array
(
[0] => <a target=_blank href='http://www.naver.com'>네이버
[1] => <area shape="RECT" target="_blank" coords="10,10,135,60" href="http://www.daum.net" />
)

[1] => Array
(
[0] => <a target=_blank href='http://www.naver.com'>
[1] => <area shape="RECT" target="_blank" coords="10,10,135,60" href="http://www.daum.net" />
)

[2] => Array
(
[0] => http://www.naver.com
[1] => http://www.daum.net
)

[3] => Array
(
[0] => 네이버
[1] =>
)

)