You can “Robotize” your own voice by using Ableton’s vocoder, just google “ABleton Vocoder” and you should get a tutorial. Otherwise you can use a variety of websites which will generate robotic voices for you however many of them cost if you want to get all the copyright issues sorted out.
You want a vocoder. Ableton has one. Electrix made some hardware ones that were really cool that you might be able to find for cheap (called the Warp Factory). Or you could buy a copy of AutoTune.
Didn’t a recent article use the Build-In-Ones from OS X? Or did I read that somewhere else?
Depending of your definition of kids-toys, you may want to try the ones provided by your OS, though you need a bit of tinkering with the filters and stuff to make them sound not quite as flat.
Ideally I’m looking for one where I don’t have to record my own voice. I know you can get some online using computerised/pre recorded voices.
I think maybe Fruity Loops has one too that will red the text you put in, but I’ve a mental block with Fruity Loops and take it as nothing more than a kids toy so refuse to use it, he he