Firstly, thanks for pointing this out for me! I am currently, well was, in the planning process of making a soundboard just like this embedded into the 360's controller keyboard thing. Guess that's one project that I no longer need to attempt!
Perhaps you could buy one of these taunting devices and have a look at how they work, they may have some useful components inside them, they may even be mp3 based if you're really lucky.
Yes, but that product can only play 30 second clips - You could still attempt