Jim Thompson wrote:
Anyone have good guess for the capacitance of a 1" diameter piezo
disk?

Likewise, how much capacitance in around 100' of typical telephone
twisted pair?

...Jim Thompson
To both questions, measure it?
the cable for example,connect to a scope(multimeter),
feed it from a source(there a re nice tonegenerator programs
for xp and soundcard),and compare voltages, then calculate
capacity.
Same method for the piezo.
Or check out an internetshop for them, and see if they
have technical specs.
Also, anumber of multimeters have