ASIHTTPRequest is an easy to use wrapper around the CFNetwork API that makes some of the more tedious aspects of communicating with web servers easier. It is written in Objective-C and works in both Mac OS X and iPhone applications.
It is suitable performing basic HTTP requests and interacting with REST-based services (GET / POST / PUT / DELETE). The included ASIFormDataRequest subclass makes it easy to submit POST data and files using multipart/form-data.

An article demonstrating how to reverse engineer an iPhone app. So, even though it may not be as easy as reverse engineering a SWF, the lesson here is don't hide stuff in your iPhone app (API keys, passwords, etc., thinking that they'll remain private).