And then the rational part of me also said that lines might be long, and the ballot here in San Francisco, particularly if you live in a district electing a supervisor (which I do), involves four separate ballots and takes a while to fill out. It was decided: I would vote early.
So I went down to City Hall -- mind you, this was neither in the exuberant rush of people eager for the first day of early voting, nor was it close to Election Day itself, nor was it even at the lunch hour or some other busy moment -- and I had to wait 10 minutes to get a ballot. And now come reports of long early-voting lines in many states, as well as surges of new voters registering at the deadlines, suggesting that there will indeed be long lines on Election Day.
My point is: why not go ahead and vote now if you can? Or if you're not already doing absentee? The Google has most of the answers about how to vote early if your state allows it.