Depends how long you expect the task to take. I used to use something like this (which I'm sure you can update now that browsers have advanced and the DOM has stabalized a lot more :):

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

# unbuffer output
$|++;

print $q->header().
      $q->start_html.
      $q->start_form({-name=>'statusform'}).
      $q->textfield('status','',50,50).
      $q->end_form;

for (0..100) {
    print_status("$_\% completed");
    sleep(1);
}

print $q->end_html;
exit(0);

sub print_status {
    my $status = $_[0];
    $status =~ s/'/\\'/g;
    print $q->script({-language=>'javascript'},
              "document.statusform.status.value = '$status'\n"
          );
}
[download]

This is only off the top of my head and I haven't tested, but that's the rough idea. It's a bit of a hack, but I remember getting it to work in IE and Netscape (but that was 3yrs ago - there's probably a more acceptable method used today. Probably :)

Looking at it it now, I'd probably use an iframe with the above hack and js page refresh every 30 seconds to avoid getting too big a page of js.

.02

cLive ;-)