> I am interested in finding out more about extremely small-scale pressure
> transducers.

Try Lucas NovaSensor in Fremont, CA.
http://www.novasensor.com
1-800-962-7364

They make, among other things,
micromachined pressure sensors.
You may be able to order individual dice,
but it'd be easier to handle packaged parts.
They can be as small as 5x4x2 mm.

        --Kirt Williams