Not so much for Apple Software update, but when re-installing OS X after some time, smaller programs like Perian or firefox install, then come up with an update. I like to keep the install files for my programs handy, and the usual method is to find the developer site and download the newest version, but when it updates itself, it downloads the new version, then automatically launches it. I'd like to know where it downloads to so I can just take that file and store it, rather than having to go to the site all and re-download it. I've looked around but can't seem to find any place that it would go, so I assume it's some hidden temp folder or something. . I remember on Windows it was some temp folder in the Windows system folder (at least for the Service packs and other WindowsUpdate items).