The Services menu is available in almost all Mac OS X
applications. It provides a way that other applications can provide
extra functions, or perform some action on the selected text. Narrator
offers a service to other applications: choosing the > Services
> Narrator > New Document with Selection
command when you
have some text selected in another application (that supports the
Services menu) will launch Narrator (if it isn't already running) and
create a new document containing that text. You can then use the
Casting Assistant or add Characters yourself. This feature makes it
very easy to use Narrator to speak some text from wherever you come
across it.
Note: Due to the way Mac OS X works, you need to install Narrator in the Applications folder, or a few other standard locations, for it to offer the service. Also, you will need to launch Narrator before the operating system will detect the service for the first time.
