Thank you eg! Uuencoded zlib is the answer, it's about 85% smaller than plaintext.

use Compress::Zlib;
use HTML::Entities;

sub zlibc{ # zlib compress
$output = compress($input);
$output = pack ("u", $output);
$output = encode_entities($output)}

sub zlibu{ # zlib uncompress
$o = decode_entities($input);
$o = unpack ("u", $o);
$output = uncompress($o)}
[download]

Update: suffered some downvotes because i didn't realize how badly color-coded perl would go over.

That won't happen again =)