From: Winnipeg, MB
You can, of course, void your vote by writing some witty comment about the quality of the candidates, and the election can even be cancelled if too many people do that, however, the required void rates are so high (I think it is something like 66%) that for all purposes it is not going to affect the results.
and actually, some years ago, there was this "election ink" you were supposed to dip your middle finger in. But this was more to avoid fraud (somebody voting multiple times) than to recognize you as a voter. Technology and better times had made this obsolete, at least in Peru
I saw the election ink method being used in an Arab country (can't remember which) where a woman was proudly showing her purple finger because she had just got the right to vote. I thought - there's a good idea. Young people will see all the purple fingers and know that when they come of age they should vote too.
Then the next day I heard that there were instances of women having their purple finger cut off by Arab men who did not accept their equality or freedom - what a horrible doctrine! After that I was not in favour of the purple ink method.
No matter how bad a situation is, you can always make it worse. - Chris Hadfield : An Astronaut's Guide To Life On Earth