Everyone else is doing it.

Copy this sentence into your livejournal if you're in a heterosexual marriage, and you don't want it "protected" by the bigots who think that gay marriage hurts it somehow.

Actually, I already voted No on Prop. 8. CA has early voting. I went in a week ago. Paper ballots with a straightforward marking system; you draw a line to make an arrow pointing to your selection. Even an idiot can figure it out, which means that nearly one third of all voters will get it right.