Even though this thread is three years old, I have decided to share my experience because it was at the top of my initial search results when I was having this same issue. I was able to get my pictures back.
In my case, it was a 4GB standard-size SD-Card. And it stopped working from one day to the next while remaining seated in my digital camera. The camera gave me the following two error messages (one on top of the other):
Memory card error
First I made sure that the card itself had a defect, not the filesystem, or the card reader in the camera, or whatever else it could conceivably be. I tried all of the following:
- reading the card in the original camera
- reading the card in several different card readers on my PC
file -s /dev/sdg (designation of my card reader) with each card reader to make sure it was completely unresponsive
- blowing through the card reader
- carefully cleaning the card's contacts
- sliding the lock switch back and forth
- putting a piece of tape over the lock switch cutout to make sure the reader would see the card as unlocked
And when none of those things helped, I decided to look into professional data recovery options. I found a small company in Dresden, Germany, that specializes in Flash recovery: Recoverfab
Apparently, a common cause of SD Card deaths is a malfunctioning controller chip. What they do to get at the data is remove the storage chips from the card, and then read out the raw state of those chips into an imagefile. Then they sort that imagefile out into the bits and bytes that the controller would otherwise present to the card reader.
Of course I wasn't happy that my pictures would incur further costs, but I have to say their prices are very reasonable. I was quoted a price of 126€ to be paid only if recovery was successful, and after being able to review thumbnails of the images recovered.
And I am very happy to have my pictures back.