The most annoying Xcode error ever: The Info.plist for application at (null) specifies a CFBundleExecutable of (null), which does not exist.

If you're developing an iPhone application in XCode and getting the
error:

“The Info.plist for application at (null)
specifies a CFBundleExecutable of (null), which does not exist.”

here's
how to fix it:

In Xcode, choose "Executables" from the project
hierarchy. Click your project executable then press Command-I. Choose
the General tab and set the working directory to "Build Products
directory".

This fixed the problem. The advisory from Apple did
not help much, but did mention the Build Products directory. Under SDK
release notes for iPhone OS 3.1, XCode/Developer Tools:

"Changing
an iPhone Executable's working directory from “Build Products
directory” may cause the application not to install properly with the
error message “The Info.plist for application at (null) specifies a
CFBundleExecutable of (null), which does not exist.”"

Hope
this saves you a little time. It frustrated me for a while.