So your computer's drive died and don't have a backup?!?! Well you may be in luck! read on to see how this free app might be your key to recovering your data.
A while back my wife's external drive started "acting up". Not only was it making odd sounds, but it started not showing up in finder which is never a good sign. So step one, when you start seeing odd drive behavior is to back it up! in this case when I tried to do that the computer said that the drive was empty. Basically the partition map was no more and any references to my files were gone! I tried to repair the drive using the mac disk utility however that didn't work. So I scoured the net and came across two tools, testdisk, and photorec. Long story short, by running photorec (which can read mac, win and linux drives) it recovered all my photos and files on the drive. How does it work this magic you might ask?!? Basically it searches the disk block by block and looks for file types it recognizes and pieces back what ever remains on a drive. The crazy part is that because data is released and not actually deleted on the drive, you can often find files that used to exist on previously reformatted disks.
Once I saw how well this worked, I began digging out all my old disks (I have prob 20 or IDE and maybe 20 more old SCSI disks) and began searching them to see what I could find. Surprisingly I found a ton of old photos I had forgotten and abandoned on these old disks. Not only will it recover old photos, but it will recover about any type of file you can think of. I found old Photoshop docs, word, excel, visio files... and even PDFs.
NOTE: Hopefully you can see how dangerous it is to give away computers with hard drives intact. Whenever you give away computers, always remove the drive or use an erase program that will write random data over the entire surface of the drive multiple times. The last thing you want is a person with this program running this on your drive and pulling up all of your old bank records, personal documents, or family photos.
Link to Photorec: http://www.cgsecurity.org/wiki/PhotoRec