Phew, we can rescue or secret plans for world domination - or pinch someone else's.

The standard answer to this sad question used to be: “Sorry, no, that’s why it’s important to keep a running backup of all of your important files.” But lately we’ve seen some impressive hard-disk voodoo from companies like SubRosaSoft. Specifically, FileSalvage ($79.95 download, $89.95 on CD) works like a charm, and you can use the free demo to search out the file, and then pony up for the software once you know the file is salvageable.

That’s right, there is a chance your file is gone for good, mainly if you happened to overwrite its data on the physical disk. Items that you delete from the Mac’s Trash remain hidden in your disk’s file system until something else (new files you create and save, software you install, files you download) takes their place. So the corollary warning is: Remember to use Secure Empty Trash on files that you want to make sure your bored little brother or some other creep can’t pull out of your system with a handy tool like FileSalvage.