The funny thing is that if you're suddenly a millionaire, your life - at least socially - will suck. Everyone will always come to you asking for money, or for this, or for that, or for a ride in a limousine. If I won something like this, I'd do what Ken would do - keep it a secret from everyone else.
I wouldn't let anyone else know I won, simply because people would stop being friends with you because of who you are, but instead of how much money you have. The only time I would ever tell anyone is if I was in long-term serious relationship, but even then I wouldn't say a thing until I know she loved me and not my money.
Instead of spending it all (or even a large portion of it), I'd find some way to put the money to use. It's not everyday that one comes into a large fortune, so I'd start looking for gaps or niches in the market where even more money can be made. A great example is in either transportation or energy. As our oil supplies peak, and then slowly decline, there is a
ton of potential to make a ton of money, as well as find a new solution thats better for the environment
and improves our quality of life.
If you can establish yourself quickly, and offer a cheap, cost-efficient solution to the oil-shortage crisis that starts to become widely adopted, your million dollars is now ten million. And then one hundred million. And then one billion. And beyond.
With enough money, you can conduct more and more research to find even more solutions to problems in the world. With money, you can give back to the world, and make the world a better place. With money, the possibilities are endless.
I want to
do something in life, instead of just watching life come and go and being another average person in a planet of six billion. I want to be one of the ones that dares to take some risk, to blaze a new path, to be a leader, to change the world. Maybe you'll think I'm crazy for thinking this, as you wouldn't be the first one.

But to quote Apple Computers,
"... the ones who are crazy enough to think that they can change the world, are the ones who do."