zip-in-php.php

<?php

$a = array('a' => 'a1', 'b' => 'b1');
$b = array('a' => 'a2', 'b' => 'b2');
print_r(array_map(NULL, $a, $b));

/* RESULT:

Array
(
    [0] => Array
        (
            [0] => a1
            [1] => a2
        )

    [1] => Array
        (
            [0] => b1
            [1] => b2
        )

)

*/