Historically, we have always assumed that an amputated finger, for example, could not be regenerated. However, medical scientists are now finding that certain cells actually have the necessary information for regeneration. The can even share this capability with other cells, tissues, and organs. The secret is coaxing them to do it, and this informative CBS report highlights significant advances: Here is the YouTube link and here's the Tube:

The scientists, it should be noted, are not creating this ability; the information was there in the cell already, but special techniques are required to enable it to be used.