1. use the wperl.exe provided with ActivePerl to run your script. this is a copy of perl.exe that just doesn't create a console window at all. remember, however, that you have no STDIN/STDOUT/STDERR, so you can't even catch errors. be sure your script is totally bulletproof before calling it with wperl.exe. also note that more info about this method are available here.
2. use Win32::GUI and the following lines:

   use Win32::GUI;
   my $hw = Win32::GUI::GetPerlWindow();
   Win32::GUI::Hide($hw);
   [download]

3. use Win32::API, but this requires a lot of work:

   use Win32::API 0.20;
   
   # just for completeness...
   use constant SW_HIDE => 0;
   use constant SW_SHOWNORMAL => 1;
   
   # the API we need
   my $GetConsoleTitle = new Win32::API('kernel32', 'GetConsoleTitle', 'P
   +N', 'N');
   my $SetConsoleTitle = new Win32::API('kernel32', 'SetConsoleTitle', 'P
   +', 'N');
   my $FindWindow = new Win32::API('user32', 'FindWindow', 'PP', 'N');
   my $ShowWindow = new Win32::API('user32', 'ShowWindow', 'NN', 'N');
   
   # save the current console title
   my $old_title = " " x 1024;
   $GetConsoleTitle->Call( $old_title, 1024 );
   
   # build up a new (fake) title
   my $title = "PERL-$$-".Win32::GetTickCount();
   
   # sets our string as the console title
   $SetConsoleTitle->Call( $title );
   
   # sleep 40 milliseconds to let Windows rename the window
   Win32::Sleep(40);
   
   # find the window by title
   $hw = $FindWindow->Call( 0, $title );
   
   # restore the old title
   $SetConsoleTitle->Call( $old_title );
   
   # hide the console!
   $ShowWindow->Call( $hw, SW_HIDE );
   
   # sleep one second, then show the console again
   sleep(1);
   $ShowWindow->Call( $hw, SW_SHOWNORMAL );
   [download]

   what the above code does is exactly what Win32::GUI does (a nasty trick I've found in the MSDN documentation :-).

cheers,
Aldo

King of Laziness, Wizard of Impatience, Lord of Hubris