if you have any PHP support on a server ANYWHERE, here's a nice little script that will automatically gzip deflate js and css files if the browser supports it:
What this does is it gets the file path from
if(substr($_GET['src'], -3) == '.js')
elseif(substr($_GET['src'], -4) == '.css')
$mime = 'text/css';
header('Content-type: '. $mime);
$_GET['src'] and reads the file after sending appropriate headers, and compresses it along the way, thanks to the second line.
Which compresses and outputs the contents of the file at path/to/file.js