> If so, is there any interfacing circuitry required between the CMOS
> and the PIC?  (I'd rather ask before blowing any more parts, as my
> electronic habit is driving me into debt)

|  No interface - as long as you only wish to switch voltages within the
|5V supply voltage range you are using for both.  Actually, I am
|surprised to find the Signetics "HC" part is rated to 12 volts; but to
|use that you have to switch with 12V CMOS logic; would require level
|conversion from a PIC.

Many 4066 variants are rated for over 5 volts, and indeed they
are quite commonly used for general-purpose switching of signals
up to about 12 volts.

As for PIC interfacing, if you only need to control one 4066
switch, you could probably use port pin RA4 which is open-drain
and can handle over +5 volts.  Note that, per the current data
sheet erata, use of RA4 at voltages above 10 volts or so (read
individual erata sheets for details) may cause excessive device
wear; if you're running your 4066 off 12 volts, you may want to
control it with RA4, using e.g. a 47K pullup and a 220K pulldown
(wired to ground, to limit the voltage on that pin to about 9-10
volts).  Even with VDD at 12 volts, a 4066 will regard a 9-10 volt
input as a valid "high".