Thanks guys. My wife tried to upload photos from her camera to iphoto. When she pressed the "upload and delete originals" button, the program crashed and, when she got it up again, she couldn't see any files on the card. I made sure that she didn't do anything further (i.e. write any new photos to the card). So, from everything I have read, the photographs should most likely be retrievable. I appreciate the suggestions and will see if I can get her photographs back for her.