Tatsuhiko Miyagawa and Johan Vromans point out a very nice approach to creating a Plack stand-alone executable on p5p:

% cat > app.cgi
package main;

my $app = sub {
      return [ 200, [ "Content-Type", "text/html" ], [ "Hello" ] ];
};
Plack::Handler::CGI->new->run($app);

% cat `perldoc -l Plack::Handler::CGI` app.cgi > app_bundled.cgi
[download]

... or, creating a Mojolicious::Lite app:

$ cat > myapp.pl
    use Mojolicious::Lite;
    get '/' => sub {
      my $self = shift;
      $self->render(text => "Hi");
    };
    app->start;
[download]

The myapp.pl can work as a CGI, but also as a PSGI handler if you deploy to platforms that only supports PSGI apps and *not* CGI, such as Heroku, DotCloud and Stackato.