Is there any free software to recover deleted picture files(digital camera's)?

Aint no way! The images are stored on flash memory and once gone, they gone! If you had a camera with a hard drive for storage, there might be a way but I aint seen many cams that use a hard drive.

Do you mean deleted from the memory card of the digital camera?

This is a good, free software program>>
http://desktop.google.com/