iPhone High-Res Backgrounds: How to and sources

What is the best way to implement a look and feel similar to the PPD Clinical Trials Mobile app (allows search for clinical trials) where it appears they have implemented a UINavigationController and UITabBar controller as overlays over the MainWindow and a high res background.

Also as a follow up to this question is there anywhere that has some stock iPhone 4 graphics (buttons, icons, and especially backgrounds) that can be used for mocking stuff up?

EDIT 0: By the way, I don't know that they use a UITabBarController for the bottom, but from all indications they do use a UIN开发者_StackOverflow社区avigationController up top. It behaves as you would expect.

It seems to me that the PPD Clinical Trials Mobile app is composed of the following elements:

1. a modal view controller on top of the background;

2. the modal view controller has got a frame smaller than the screen size;

3. the modal view controller contains a UINavigationController;

4. the effect of transparency is obtained by setting the alpha property of the views inside the modal view controller to something below 1.0 (which means opaque).

Stock graphics/components:

http://spoiledmilk.dk/blog/iphone-ui-design

http://www.teehanlax.com/blog/iphone-gui-psd-30/

Icon sets:

http://glyphish.com/

As for the screenshot, I reckon you could accomplish it's contents in the following way:

• Background: Static image, created in Photoshop or similar (pixlr.com as a great free online alternative)

• Navigation bar: Overridden the default UINavigationBar and set the frames of the components differently.

• Selection menus: Overridden default class objects again.

Hope this was of some help!