Frank is an iPhone/iPad UI testing tool that sews together several open source tools, notably UISpec, cocoahttpserver, and Cucumber. The goal is to automate basic UI-level acceptance testing of an iPhone or iPad application, integrated into a Continuous Integration system.
Check out Frank in action! This short screencast shows a sample iPhone app being exercised in the iPhone simulator by a set of cucumber tests.
Pete Hodgson's full post on Frank is featured here.