<?php
$a = array((object)array('Name'=>'fff','Value'=>2),
           (object)array('Name'=>'aaa','Value'=>1),
           (object)array('Name'=>'bbb','Value'=>3));

usort($a,create_function('$x,$y','return $x->Value - $y->Value;'));

print_r($a);

Array
(
    [0] => stdClass Object
        (
            [Name] => aaa
            [Value] => 1
        )

    [1] => stdClass Object
        (
            [Name] => fff
            [Value] => 2
        )

    [2] => stdClass Object
        (
            [Name] => bbb
            [Value] => 3
        )

)