If your web page needs to send something small (less than 1KB of data) back to the server, you could do it by loading an image. The image url could contain an encoded data.

www.yourwebsite.com/cgi-bin/servebmp.cgi?saveThis=askldajlkdjasldkjaslkjasdljaslkas

And when you load the image, your perl script on the other end could decode the url and store the data. Oh, and when it's done, it should send back an image. perhaps a 1x1 bmp image. It has the smallest header:

###############################################################
#
# This function creates a simple B/W bitmap image
# to send back to the browser as a response.
#
# Usage: SpitBMP(width, height)
#
# Example: SpitBMP(4, 3) ---> Creates a black 4x3 BMP image
#

sub SpitBMP
{
  my $W = @_ ? shift : 1;
  my $H = @_ ? shift : 1;
  $|++;
  my $HEADERLEN = 62;
  my $DATASIZE = Ceil($W * $H / 8);
  my $FILESIZE = $DATASIZE + $HEADERLEN;
  my $BITS_PER_PIXEL = 1;
  my $HEADER = 'BM' . pack('VxxxxVVVV', $FILESIZE, $HEADERLEN, 40, $W,
+ $H) . chr(1) . pack('xCxxxxxV', $BITS_PER_PIXEL, $DATASIZE) . "\0" x
+ 20 . "\xFF\xFF\xFF\0";
  my $OUTPUT = $HEADER . "\0" x $DATASIZE;
  print "Content-Type: image/bmp\n" .
        'Content-Length: ' . length($OUTPUT) . "\n\n" . $OUTPUT;
}

###############################################################
#
# Rounds a number up to the nearest integer.
#
# Usage: INTEGER = Ceil(FLOAT)
#

sub Ceil
{
  my $DEC = shift;
  my $INT = int($DEC);
  return $INT if ($DEC - $INT == 0);
  return $INT + 1 if ($DEC > 0);
  return $INT - 1;
}
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