You can customize what string is generated and how long it is
[PHP] Code
Function random($length)
{
$hash = ;
$chars = ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz;
$max = strlen($chars) - 1;
mt_srand((double)microtime() * 1000000);
for($i = 0; $i < $length; $i++)
{
$hash .= $chars[mt_rand(0, $max)];
}
return $hash;
}