also DropStuff comes free in the Stuffit Lite package, which is how you make sit files. Of course, if your 700 MB files are anything but text, you probably won't get a single byte of compression out of stuffit. Burning the disk in ISO9600 format instead of the default Mac/PC hybrid will gain you about 2.5 MB. Burning in CD-XA mode will gain about 100 MB, but that disc won't be readable by OS X (I think) and it won't have any error correction. But it's (roughly) the format of SVCDs, which is why they usually live in the 700-800 MB size range