I am using subroutine attributes with CGI::App to automatically register run-modes (rather than having to set them up manually)

 
  package MyApp;
  use base 'CGI::Application';
  use CGI::Application::Plugin::AutoRunmode 
                qw [ cgiapp_prerun];
        
   sub my_run_mode : Runmode {
                # do something here
   }
    
   sub another_run_mode : Runmode {
                # do something else
   }
   
   # you now have two run modes
   # "my_run_mode" and "another_run_mode"
[download]

The module is still somewhat experimental, and hence not yet on CPAN, but if you want to give it a spin: perldoc download