There is a cute (admittedly disgustingly cute) way to check the validity of approval ballots in Rivest's 3ballot secure voting scheme. I'm the inventor and I call it "tricolor."
The ballots have punch-outs where voters punch a hole. (Hanging chads? Sue me.)
We have 3 colors of translucent sheets.
The point I'm aiming for, is, if you punched exactly 1 or 2 holes (i.e. exactly the "valid ways to vote" in Rivest's 3ballot scheme for making approval voting secure) then stack the 3 ballots on top of each other, then
Making sheets chiral shape prevents misorienting before stacking. The point is, this tricolor invention makes the check so trivial no machine is needed (or a trivial machine). [We admit there are useability issues for colorblind voters.]
Now (time to get even cleverer), about the copy: Remember, you've got 3 ballots, red-, blue-, and green-blocking. You want to copy exactly one, where you (the voter) choose which. Let's say you chose RED. Stack on top of each other, and shine a monochromatic RED light through onto photosensitive copying stuff which senses light but is colorblind. Result: the red-blocking ballot gets copied. Other ballots ignored. Machine does not know which color you chose (if its sensors really are colorblind, that is). It sucks all 3 of your ballots in as it copies and checks, and spits out the copy. (If check says no good, then all 3 ballots visibly destroyed in front of you and no copy comes.)