Homebrew PCBs

I decided to try an idea I had for creating custom keypads for my
projects. I have only done a single key, but it worked quite well.

I took a circuit board, a piece of laser transparency and some
aluminum duct tape.  I punched a hole with a hole punch in one piece
of the transparency. The duct tape has adhesive on one side so I stuck
that to a second piece of transperency. I stacked the pieces together
in order of 

transpency with alumunum side down
transparency with hole
circuit board

Since this was a test case I just taped everything down to the board. 
I hooked up my meter to the copper and the aluminum tape. With a
reasonable amount of finger pressure I was able to make contact. I
pushed several times and had no problems with the button opening the
connection when I released. 

So it goes without saying it should be possible to etch a board to
handle multiple pads and connect the aluminum tape to ground, then
have your favorite controller scan the pads for presses. I am sure
some kind of debounce will be need, but that is no different than any
other type of switch.