I am trying to create an interface similar to the app Instapaper. The works just like a navigation bar except its on the left hand side.
I’m having an issue creating this interface. Any ideas on how to do this type of interface. I was thinking of a window with a view controller split up with two different views.
Any ideas, suggestions, or even a tutorial?

Mine (in Instapaper) is just one big view controller with a sidebar view that toggles the contents of the larger view manually. It’s not too bad in my case, since it can only have two states — grid or browser — that simply switch which data is shown in the grid/browser.
If you can require iOS 5 as the minimum, you can use some of the new child-view-controller mechanics, but I couldn’t yet.