Instructables user randofo created this cool DIY project that uses a clock from IKEA and of course the random wires and bits for any DIY electronics project.
This is a simple to build device that converts your own human voice into a superior robot voice. It also includes a number of sweet features like an audio-in jack so that you can plug in all of your favorite instruments, microphones and music players, a vibrato mode and awesome pitch shifting buttons. It can be shifted two whole octaves in either direction. This provides for endless hours of fun (at the expense of everyone around you).
Check out the results in an MP3 file here.