Are there free iPhone navigation bar icon sets available?

I want to use up/down icons like the ones used by "mail" in the upper-right corner when you're viewing a specific message. Are these icons available for free anywhere?

iPhone: Setting Navigation Bar Title

Hey all. I'm still pretty new to iPhone development, and I'm having a bit of trouble figuring out how to change the title of my Navigation Bar. On another question on this site somebody recommended using :

Checking if a UIViewController is about to get Popped from a navigation stack?

I need to know when my view controller is about to get popped from a nav stack so I can perform an action.

UINavigationBar - Set title programatically? iPhone SDK 4

I have a tab bar application with a different view on each tab. Each view has a UINavigationBar with title set on Interface Builder. I am wanting to change the title based on a clause in the ViewDidLoad method, so if x { change the title }.

Hiding UITabBar when pushing a UIView

I have a UITabBarController where the default view controller is a UINavigationController . I want to be able to hide the UITabBar of the UITabBarController when I push a certain view in the UINavigationController .