Depends what kind of setup u got, software or hardware.
There is a piece of software called a Vocoder which is available in some top-end synth/keyboards, possibly a couple of the Fantom series synths, not too sure.
This software allows a vocal recording to be passed through some kind of processor which digitally filters the vocal recording.
There is also many versions of this software in computer programs like Cubase, ProTools and possibly even plug-ins for Fruityloops. It works in the same manner as the software in the really expensive synths.
I've never actually tried to process vocals like that but as far as I know that is only two ways of creating the electro/robot voice. There are quite possibly several ways and tools to create the sound, one other would be through an Effects Processor, they can be quite expensive too.
Kramit