I'm looking for a way to compress the Xcode 4 installer to the smallest possible size (since the App Store insists you keep the stupid installer, or else it's not considered "installed".) This installer takes up 4 and a half gigs of space, and I'm starting to run low. I don't care how fast it compresses/extracts, or whether the compression app is GUI or Command Line driven. I just need the smallest possible file size. I've tried the Archive Utility zip format, tar.gz compression, and p7zip, but they don't seem to compress it more than .03 GB. Is it possible to force programs like Tar to compress into smaller files, or is there another format that compresses better?