(Newbie) Detecing requested controller?

[eluser]Unknown[/eluser]
Newbie question - what is the best way for determining the controller being requested? I am trying to create a navigation bar and want to change the div based on the controller. Thanks in advance!

[eluser]Phil Sturgeon[/eluser]
Easiest way would probably be:

Code:

$this->uri->rsegment(1, '');