I cannot get them to open on my computer. What did I do? You most likely will not get them back for free. You can try to download software which can try to recover them. There is no unformat option.
Below is a guide for a specific application which may help.
http://www.easeus.com/datarecoverywizard...
Here is another one which seems like it may also work. This one works with all standard file systems.
http://www.diskinternals.com/ The link will download a free app which I've used to recover pictures from a formatted card. If you google for terms like "image" "recover" and "card" you'll find loads more - some are better than others, so try a few if the first one doesn't work. | 