Memory card error (by 3 users)

Try another card. The card can have a life limit, after all it is flash memory.
Also try to use the card in a card reader, not the camera. If that works, and you can save your pics... (remember never try to delete or change any of the pics. on the card from the computer, a lot better chance of corrupting the files...that may be due to the fact that the camera and the computer can be seeing different ways of making folders and reading them...just mention that because I had it happen... always format and delete all pics in only the camera you use that card in.)
If you are successful to transfer your pictures, then format the card in the camera, and see if it will work.
The final on this is that if the card will not format, and will not save pictures, then it is finished. You can try to use it in another kind of camera, sometimes that may work as well.