In Australia, you can go to any polling station in your electorate, where they find your name in a book of paper (of which there are several copies in each stat

In Australia, you can go to any polling station in your electorate, where they find your name in a book of paper (of which there are several copies in each station, and several stations in each electorate), cross it off, and give you a ballot paper from a stack. Presumably they process the names lists after the fact to see if anyone voted twice, though by that point there's no way to get the votes out of the mix.