Well, poop. It seems that anything made in the last 10 years is kind of unhackable, at least at my skill level. Most of the voice synthesizer stuff (if it's even synthesized, it may just be a recording) are tucked into a little glob of black epoxy, totally unaccessible. I've only had limited success with two things--a little Mickey Mouse eight-note organ (I can get it to do a buzzing noise and a weird vibrato sound), and could probably adjust it in some other ways, but it's still only going to be an eight-note organ no matter what I do, so I question the use of this as a project.
I also have a little toy telephone that plays a couple tunes, and I've figured out how to speed up and slow down the sounds a fair bit, but that's the extent right now.
I don't really know a lot about electronics--maybe I'll try to pick up a Dummies guide after christmas--but this stuff is really hard to hack :( --- Edit: Gee, that post looks whiney! All of this should be taken with a grain of salt, as I've only just today started working with electronics and don't have the foggiest idea of what I'm doing!