Update: On further consideration, I see that I misunderstood the question. Sorry about that. I think the answer is actually: no.

You'd have to locate the content by hand using the find URL functions and do your the way you want... I have a semi-mech solution in the readmore below. Hopefully there's a better way.

But the problem is that the download is initaited by a button click, not a get. Steve

Did you try to use this method?

$mech->save_content( $filename )
Dumps the contents of $mech->content into $filename. $filename will be
+ overwritten.
[download]

Same problem

use WWW::Mechanize;

my $mech = WWW::Mechanize->new();
$mech->get('http://search.cpan.org/');
$mech->set_fields( query => 'ACME' );


click_button(
  $mech,
  value => 'CPAN Search',
  ":content_file" => "filename.here"
);


sub click_button {
    my $self = shift;
    my %args = @_;

    for ( keys %args ) {
        if ( !/^(number|name|value|input|x|y)$/ ) {
            $self->warn( qq{Unknown click_button parameter "$_"} );
        }
    }

    for ($args{x}, $args{y}) { $_ = 1 unless defined; }
    my $form = $self->{form};
    my $request;
    if ( $args{name} ) {
        $request = $form->click( $args{name}, $args{x}, $args{y} );
    }
    elsif ( $args{number} ) {
        my $input = $form->find_input( undef, 'submit', $args{number} 
+);
        $request = $input->click( $form, $args{x}, $args{y} );
    }
    elsif ( $args{input} ) {
        $request = $args{input}->click( $form, $args{x}, $args{y} );
    }
    elsif ( $args{value} ) {
        my $i = 1;
        while ( my $input = $form->find_input(undef, 'submit', $i) ) {
            if ( $args{value} && ($args{value} eq $input->value) ) {
                $request = $input->click( $form, $args{x}, $args{y} );
                last;
            }
            $i++;
        } # while
    } # $args{value}
    return $self->request( $request, grep defined, @args{qw[:content_f
+ile :content_cb :read_size_hint ]});
}
[download]

W::M is basically LWP::UserAgent. so you can also refer to perldoc lwpcook the 'large documents' section.

LARGE DOCUMENTS
    If the document you want to fetch is too large to be kept in memory,
    then you have two alternatives. You can instruct the library to write
    the document content to a file (second $ua->request() argument is a file
    name):

      use LWP::UserAgent;
      $ua = LWP::UserAgent->new;

      my $req = HTTP::Request->new(GET =>
                    'http://www.linpro.no/lwp/libwww-perl-5.46.tar.gz');
      $res = $ua->request($req, "libwww-perl.tar.gz");
      if ($res->is_success) {
         print "ok\n";
      }
      else {
         print $res->status_line, "\n";
      }

    Or you can process the document as it arrives (second $ua->request()
    argument is a code reference):

      use LWP::UserAgent;
      $ua = LWP::UserAgent->new;
      $URL = 'ftp://ftp.unit.no/pub/rfc/rfc-index.txt';

      my $expected_length;
      my $bytes_received = 0;
      my $res =
         $ua->request(HTTP::Request->new(GET => $URL),
                   sub {
                       my($chunk, $res) = @_;
                       $bytes_received += length($chunk);
                       unless (defined $expected_length) {
                          $expected_length = $res->content_length || 0;
                       }
                       if ($expected_length) {
                            printf STDERR "%d%% - ",
                                      100 * $bytes_received / $expected_length;
                       }
                       print STDERR "$bytes_received bytes received\n";

                       # XXX Should really do something with the chunk itself
                       # print $chunk;
                   });
       print $res->status_line, "\n";

oops. accidentally hit the 'save' key.. so combining the above with anonymous code.. you can do

my $req = $mech->click_button(name => 'begin');
$mech->request( $req, '/PATH/TO/SAVED/FILE' );

request method in W::M is an overload of LWP::UserAgent's request method.