Take a look at this:
http://www.speakjet.com/ 
It?s a robotic voice simulator chip that you can control from either its input pins or a RS232 port (for those of you not into computers: The serial port on your computer). There?s links to places you can buy the chip and RS-232 boards to mount it on and even software to make it "speak"
I bet you could make some cool DIY projects with it
