after my disaster last month involving deleted photos, I spent some time researching undelete programs.
there are several out there that can cost $10, $20 or $60, but there is no reason to pay for this type of program!
when you delete a file from an sd card, or even from a folder on your computer, it is not actually erased. it's moved aside to make room for new files. all you need is a command to bring that file back to its original spot in the folder or the sd card.
the free program that i downloaded is called FreeUndelete. it's free, and all it does is undelete your files. you simply click on the drive, select your files, and click the undelete button*. done! there is no spyware, no mailing list, no fee!
if you have ever had the unfortunate event of losing photos or documents due to accidentally deleting files, you should go download this program to prevent it from happening again.
*files cannot be undeleted after you format an sd card.