Morph one voice to sound like another?

Probably a dumb question, but does anyone know of any software out there which can take one voice recording and morph it so it has the same characteristics as another voice? I’d love to know if any programs can do this. Not just Audacity!

Custom text-to-speech is possible …
One someones voice had been banked, you could say anything you wanted in their voice, via text.

So, it is indeed do-able yet I’m guessing there aren’t any publicly available applications (for now)? Obviously many legal issues would arise the moment a program such as that would be released to the general public, so perhaps that’s why.