Have you looked at the widget demo that comes with Tk? It contains radio button and dropdown list examples. Just type "widget" at a command prompt if you have Tk installed, or look in the Tk source/demos directory for the widget demo.

Other than Tk, I also like Gtk2 for GUI's.

Just in case you have a hard time wrangling the code out of the demo's, here are a couple of simple examples.

Radiobuttons:

#!/usr/bin/perl
use warnings;
use strict;
use Tk;

my $mw = MainWindow->new;

my $rb = 'first button';

my $rb1 = $mw->Radiobutton(-text => "Button One",
                            -value => 'button1',
                            -variable => \$rb)->pack;

my $rb2 = $mw->Radiobutton(-text => "Button Two",
                            -value => 'button2',
                            -variable => \$rb)->pack;

my $b1 = $mw->Button(-text => 'Show', -command => [ \&showRB, \$rb ])-
+>pack;

MainLoop;

sub showRB
{
     print "Arg list is @_ \n";
     my $state_ref = shift;
     my $state = $$state_ref;
     print "$state\n";
     
     $mw->messageBox(-title => 'Status',
                     -type  => 'OK',
                     -message  => "Status is :$state:.");
}
[download]

#!/usr/bin/perl 
use warnings;
use strict;
use Tk;

my $top = MainWindow->new;
$top->geometry('200x200+100+100');

# Menubar
my $menu = $top->Frame(-relief => 'raised', -bd => 2);

my $menu_pulldown = $menu->Menubutton(-text => "Test",
                 -underline => 0);

$menu_pulldown->command(-label => "Exit",
                     -command => sub { exit 0 });
# Cascade Menu
$menu_pulldown->cascade(-label => "Cascade",
                        -underline => 1,);
            
my $newmenu = $menu_pulldown->cget(-menu)->Menu;

$menu_pulldown->entryconfigure('last', -menu => $newmenu);

$newmenu->command(-label => "CascadeCommand",
       -command => sub { exit 0 });

$menu->pack(-side => 'top', -fill => 'x');

$menu_pulldown->pack(-side, 'left');

MainLoop;
[download]