I was looking through a php manual that I downloaded yesterday (php_manual_en.pdf.zip) and noticed what looks like an error on page 149 (PDF page 216).  Right at the bottom of the page, there is a foreach() usage example.  Example 2 is as follows:

/* foreach example 2: value (with key printed for illustration) */
$a = array (1, 2, 3, 17);
$i = 0; /* for illustrative purposes only */
foreach($a as $v) {
print "\$a[$i] => $v.\n";
}

But $i will always be 0, as it is never modified in the loop!  I found the same error in the online manual at http://www.php.net/manual/en/control-structures.foreach.php