A comment regarding Mr. Kinsler's idea [060205 MMDigest].  I am using
a Parallax Basic Stamp, a very small prototype embedded processor
which is programmed with a modified version of BASIC, which has
extensions to handle it's unique capabilities.  Among other things
it has a driver board available which can handle 32 model airplane
servos, which are quite inexpensive now days.  These could probably
be used in place of stepper motors.  The driver board can be doubled
to drive 64 servos.

I am using the Basic Stamp version II to make a custom joy stick
controller for a personal mobility vehicle for my mother-in-law who
has severe arthritis.  I'm using surplus power seat motors and model
boat motor controllers.  I expect to complete it for around $350.
Commercial electric carts are grossly over priced.  But I digress.
The thing is that the Basic stamp is a very unique device which is
easy to program if one has a moderate grasp of the Basic programming
language.

Jim Cook

P.S.: Quasar Electronics also has 40 second and 120 second modules.