I voted today. In Arizona, if you want to vote by mail, or abesentee, you just need to specify that when you reigister. Then you get a ballot in the mail along with insttructions as to the correct way to fill in the bubbles, an explanation of the ballot issues and propositions and a pre paid envelope to mail it back. You can mail it back as soon as you get it or you can take it to the registrarss office or you can take it to the poll. In AZ if you decide you want to vote in person and you have recieved a ballot in the mail, you may do so, however, the ballot in person will be placed into a special area for verification against the mailed ballots, so you can't vote twice.
So DISUnc, perhaps where you live absentee ballots are only for those who can't get to the polls, in AZ they are for anyone who wishes to vote early. All states have their own election laws.