"Allow from all" entry in .htaccess necessary to load static content

[eluser]CodeIgniteMe[/eluser]
I suggest using base_url() instead of site_url() for portablity, because site_url() will include the base url and the index.php (if you set one) in your config file.
and the reason why you can't include the files from your views is because there is a .htaccess file in the application directories which prevents anything from being "hacked" into those inside the application directories.
you can have your own js, css, images, and downloads directory outside the application and system folders, but I still recommend to put them inside a common folder, like idealws did.