Or, using the built-in stuff:

use CGI qw(:push);
@ARGV = ("test.tgz","test1.tgz","test2.tgz");
$/ = undef;

print multipart_init();
while (<>) {
  print multipart_start("application/octet-stream");
  print $_;
  print multipart_end();
}
print multipart_final();
[download]

-- Randal L. Schwartz, Perl hacker