GHUnit is a test framework for Objective-C, Mac OS X and iPhone 3.x. It can be used standalone or with other testing frameworks like SenTestingKit or GTM. This video shows you how to use it to validate your mobile user interface. GHUnit has the ability to record the look of a UIView so that the developer is aware of any changes since the last test run.
Video source: http://marakana.com/s/looking_good_ui_verification_on_ios,565/index.html