Brooke Clarke wrote:

> What you are looking for sounds like the type of key that is used on
> some electronic musical keyboards.

  Ahh, now this provides a *whole new* slant on the problem.  Musical
keyboards provide not a pressure-sensitive interface, but a velocity-
sensitive one.  Is that what you want after all?  It may be.

  Velocity sensing is dead easy - it just requires two contacts which
operate at different points of the key travel (reliably).  Most
commonly, the two contacts are the end points of a SPDT action and
correspond to the supply rails, so the logic must discriminate between
pulled high, pulled low and tri-state.

  There are ways of doing this with a single PIC I/O.  If you can spare
two I/O per switch, it's even easier.
--
  Cheers,
        Paul B.