It would be nice if an FTP Client supported on the fly optmization upon uploading. None support this as far as I know. That said, I've been playing with w3compiler. It's expensive ($80), and it still a space between tags, which I found weird. However, it optimizes JavaScript by renaming long function and variable names.
well u should use ESC (ECMA Script Cruncher) dude. it's pretty awesome, it's supports multiple compression level from just removing whitespaces to space and newlines removal plus variable names replacement. just everything you'd expect from a script optimizer.
it's free...but for Windows only.
it runs from the command line, very simple. it could trim down up to 40%-60%. but watch out for sloppy codes.
read more about it here : http://www.saltstorm.net/depo/esc/introduction.wbm