I'm glad you find my work interesting :-) so many hacks, so few time, and always the question : is this cool or stupid. Well, at least that one is cool :-)
Regarding audiosco, it is just a demo. Feel free to feed 8 bit mulaw data to the pipe from any application. Once, TimW made me a demo opie-reader which would simply pass the text being displayed to an external program. I then had flite produce audio. If you can add voice recognition to the address book, you'll have what you describe. Consider what I did a "proof of concept" - nothing more. It's not made to be usable, but if someone want to code something around, go for it.
I'm very into that convergence you mentionned - like you I believe different small things will go into different body parts to play different functions. Like everybody has a wristwatch and a usb key, in the future I imagine people having headsets for phone or vocal interaction, a small screen/keyboard that you can hold in your hand or video displaying goggles (soon - I had the opportunity to test a wearable pc prototype - wow. that on a zaurus would rock, if it could be fed enough power), along with some central unit for storage and wireless communication.
Someday :-)