I know this post is old, but for future reference try using "Stellar Phoenix Photo Recovery"! I accidentally deleted my grandson 500+ football pictures while trying to transfer them to my photo server. We were able to recover them all. Even though you might delete your pictures off the card, it leaves a compressed hidden file, as long as you don't format the chip, you can most likely recover your digital pictures.
"Stellar Phoenix Photo Recovery V3.5 is a comprehensive solution to recover pictures from all internal & external storage devices (such as digital cameras, memory sticks, IBM Micro Drives, SD Cards, MMC Cards, XD Cards, Secure Digital Cards, Zip Disks, Mini Disks and Windows based hard drives) after loss due to all possible causes of data damage like file system corruption, unintentional or intentional drive formatting, unexpected switching off the camera, accidental deletion, corruption or damage to the media, read/write error messages.
http://www.stellarinfo.com/digital-media-recovery.htm
http://picasaweb.google.com/grandmabolin