Think I'm kidding?
No.
I'm totally serious.
You will no doubt hear various folks in the news media talk for hours about voting in the next few days. You might even go somewhere and put your finger on a screen or mark a piece of paper with one of their names on it. But rest assured, you have will not have voted for either of them.
If you vote this week, you will really be casting a vote for a slate of delegates to the Electoral College. Only those delegates will actually cast votes for Obama or McCain - and not until next month. (Ok, there is a slim chance others might be able to vote, but only if the electoral college vote is tied and it goes to congress ... but lets not go there ;-)
