be able to load members controller in URL but members_controller.php in controller folder

[eluser]dcallan[/eluser]
Hi, started using CI recently, only a newbie, it's not really a problem per se, but I want to rename all my controllors with a _controller postfix for maxmium clarity. How can I do this (or is it even possible) without making the user type in the _controller in the address bar.

Thanks in advance.