As we continually switch gears to work on newer products for the iPhone and the iPad, and since our team have done some of the legwork, we would like to share the resources we found on the intertubes.

Design PSDs:

Download The iPhone GUI PSD Here

Download The iPad GUI PSD Here

Courtesy of http://www.teehanlax.com

Other Resources:

A Flickr Set of Dissected iPad UI Conventions
Notes on iPad UI conventions culled from public sources (mostly Apple promotional videos)

iPhone UI Element Guidelines
Documentation from iOS Reference Library

iPhone Interface Guidelines/ Metrics by Martin Ebner
Human Interface Guidelines based on Apple's iOS Documentation

iPad UI Element Guidelines
Human Interface Guidelines based on Apple's iOS Documentation

iPad Wireframe .eps file by Sarah Parmenter
Sarah Parmenter is a UI/Web Designer and Speaker: Her blog has some useful insights as well.

Free Icons for iPhone & iPad applications
Designed and optimized for use on toolbars and tab bars in iPhone & iPad apps.

go crazy!