Generate a random-enough string. Maybe useful for passwords or for the encryption seed required in some frameworks' configuration file.

gistfile1.php

function randstr($len = 8) {
    $src = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
    $src = $src.$src.$src.$src.$src;
    return substr(str_shuffle($src), 0, $len);
}