I presume you can get this far...

#button 3 is "right click"
$someWidget->bind('<3>', 
    sub {
          my $widget = shift;
          print "right button clicked! Pop up menu now\n"; 
          #run methods on $widget
          my $Ev = $widget->XEvent;
          #stuff is learned here...
          #then new window is generated
         });
[download]

here is a short example (check Tk::bind for valid Event symbols/characters):

use warnings;
use strict;

use Tk;
my $mw = tkinit;
my $n = $mw->NoteBook()->pack;
for(qw/foo bar baz/){$n->add($_,
                             -label => $_,
                         );}
$n->bind('<3>',[\&process_bt3,Ev('x'),Ev('y')]);
MainLoop;

sub process_bt3{
    my ($w, $x, $y) =  @_;
    my $selected = $w->identify($x,$y);
    print "selected Tab: $selected\n" if( $selected );
}
[download]

update: link for bind doc

Here is the code that I came up with a few hours after posting, mostly cribbed from trolling the web. I have it in a .pm file:

use warnings ;
use strict ;  
use Tk ;      
use Tk::NoteBook ;

my $popup_menu_items = 
    [                  
        [Button => "Close", -command => \&popup_close],
        [Button => "Other", -command => \&popup_other] 
    ] ;

my $tabs ;
my $popup_menu ;

sub sk_notebook_add
    {
    my $MW = shift ;

    $tabs = $MW->NoteBook()->pack( -fill=>'both', -expand=>1 );
    $popup_menu = $tabs->Menu( -menuitems => $popup_menu_items, -tearo
+ff => 0 ) ;
    $tabs->bind( "<Button-3>" => [ \&popup_spot, Ev('X'), Ev('Y') ] ) 
+;

    return $tabs ;
    }

my $popup_tab_name ;

sub popup_spot
    {
    my $x = $_[1] - $tabs->rootx ;
    my $y = $_[2] - $tabs->rooty ;
    $popup_tab_name = $tabs->identify( $x, $y ) ;
    $popup_menu->Popup( -popover => "cursor", -popanchor => 'nw' ) if(
+ $popup_tab_name ) ;
    }

sub popup_close
    {
    $tabs->delete( $popup_tab_name ) ;
    }

sub popup_other
    {
    print "name = $popup_tab_name\n" ;
    }

1

__END__
[download]

I have only been programming Perl for a few weeks, so I am not sure what correct style is, but the 'global' variables in the module bother me. I am not sure how else to hand the appropriate widget to the popup subroutines, or even if having a cute way to do so is good Perl.

Brian