By trial and error I figured out the easiest way to rename an executable in Xcode for an iPhone.

Step 1: Select “Edit Active Target ‘MyApp'” under the Project menu in Xcode.
Step 2: Select “Product Name” under “Packaging” within the build settings for the target.
Step 3: Rename the product name to your desired application name.
Step 4: Delete the “Build” directory in your project folder or do a “Clean All”.
Step 5: (And this is where things get tricky) Quit Xcode.
Step 6: Start up Xcode with your project
Step 7: Build.

For some strange reason the product name appears to be cached by whatever system is handling code signing; thus, if you don’t quit Xcode after doing a clean all (which I’m pulling off by deleting the build directory), the old iPhone app name is used for code signing–which means you wind up with two .app folders: one which contains most of your application, and the other which just contains the signing certificate.

Go figure.