Well, if you can access the camera/card's memory like a USB device you might be able to use an "undeleter" utility to grab them depending on how the device deletes things. If it uses some sort of custom save/load format then you might be stuck.
Glary Utilities is great. When you install it go to: Privacy & Security>File Undelete
You can download from cnet's download.com for free. The free version also includes:
Disk Cleaner, Registry Cleaner, Shortcuts Fixer, Uninstall Manager, Startup Manager, Memory Optimizer, Context Menu Manager, Registry Defrag, Tracks Eraser, File Shredder, File Undelete, File Encrypter and Decrypter, Disk Analysis, Duplicate Files Finder, Empty Folders Finder, File Splitter and Joiner, Process Manager, Internet Explorer Assistant, System Information, and Windows Standard Tools