I'd try a recovery program like Recuva (free download). If that doesn't work, google PHOTO RECOVERY and pick your choice of free and paid tools. Be sure not to pay before you know the program indeed finds your pictures.
I plunged my SD card into my computer to transfer the pictures to my hard drive. Firstly, it came up all right and I also could see the pictures. But all of the sudden, an error came up and a message popped out and said the drive was unreadable, and asked me whether I need to format it right now. It seemed to get the SD card work again only by formatting it. But I have saved a great number of pictures on it, how could I just format it? Is there any way to get to them all back before the format?
Any idea could be appreciated! Please help!!!!