This isn’t really a hack but a method to change the way program looks. It uses the Interface Builder used in applications to change the way a program looks. It is very simple, but if there is an annoying aspect of a program you just want to change, or to confuse your friends this is a fun way to start. With this trick you can’t hack every program, or every feature of a program. It is fun and a good time waster if you are bored.
The way to access the interface files is to the .nib file. This is the file type used to display and configure the interface you see. Most of the time this .nib file is wrapped up within the executable. But every so often you can get access to these files and change them. For this post I am going to use Mail. Find Mail in you Applications folder and show the package contents. Then navigate to Resources > English.lproj or any language you use. These are the localization files. It just happens that Mail has these files as seperate .nib files.