Removing Controller Name

[eluser]pengenbelajarCI[/eluser]
I've watching screencast, and i very curious of how to removing controller from url.

I've tried this on rout

Code:

$route['default_controller'] = "main";
$route['scaffolding_trigger'] = "";

$routearr = array ('main','company','users');
foreach ($routearr as $v ) {
    $route[$v] = $v;    
    $route[$v.'/(.*)'] = $v."/$1";    
}
$route['/(.*)'] = "main/index/$1";

But it doesnt work, because i always get 404 error