Create a page, if you use "vote:" as the front of the article name we have a pseudo-namespace were we can easily get lists of all votes.
Put the question as a section, but answers as subsections; if the answer a voter needs is not there, they can add a new section for their answer; use
in the section you prefer to vote for: that inserts your sig and the time.
Changing votes is allowed, but obviously it's the voter's obligation to make sure they don't have multiple votes down. Bots to check this sort of thing and provide automatic tallying are planned.