If you want robotised voices, thats a bit hard to achieve tbh.
If you just want to create your own vocals, I will let you into little secret..... I havent tried it (yet) myself, but this looks the dogs bollox for all budding musicians out there.
Vocaloid
heres a demo song:
http://www.zero-g.co.uk/media/mp3/LO...eet_Dreams.mp3
Bear in mind that this was totally typed in and then tweaked to tune/musical notes etc........
Fan-fooking tastic I think. Not robotised though, but that isnt Vocaloids plan!
Sirius