Change my voice program

I need a program to change my voice, to another voice, which can be male, female, young or old. I need to be able to either speak to the program and it converts it or i type into it and it converts it. It must be able to speak it aloud.

Is there any small program, preferably free that can do this?

 

edd what have i told you about messing around in chatrooms

 

I don't want it for a chat room. I want it for a podcast.