I'm looking for something to make my voice sound mechanical/robotic etc. Are there any pedals/boxes or anything that could give me a variety of these sounds. Thanks for your help.

Boss has a voice transformer: http://bossus.com/index.asp?pg=1&tmp=59.
There are also various computer programmes available. On a mac you can do those things with Garageband.
Gear: USA Strat, Mex Strat, Epi LP, a chinese Cheapocaster, yamaha accoustic, old classical guitar
Boss BCB-60 Pedal Board
Dunlop Crybaby-Boss CS3-Little Big Muff-MT2-OD3-CH1-DD3-GT8
Fender Pro 185
Marshall DSL201
Check out a vocoder. It's like a microphone thats run through something to perfectly match a pitch, allowing you to sing in ranges that would be impossible, but it also adds a mechanical feeling. Find Neil Youngs "Transformer Man" (or about anything off the album Trans) or else "California" by Tupac. Its used alot in pop and hip hop. Or else theres always a talk box (like peter frampton)
Vocoder may be your best bet.

thats what does the "intergalactic" at the start of the song of the same name by the beastie boys.

also, you may want to look at ring modulators. thats what they use for the Dr. Who Dalek voice.
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