Sure, I know that the odds of winning are vanishingly small, but as the joke goes, you can't win if you don't play. (It's akin to our policy about running amateur-submitted astro photos in Sky & Telescope: if you send in a photo, we may not publish it; but if you don't submit it, we definitely won't publish it.)
Besides, the lottery has inherent entertainment value by generating thought and discussion. It's the old question, "What would you do if you instantly became a multimillionaire?" For me, after paying off a mortgage, and taking care of family with their mortgages and whatnot, and buying friends cars (or certain individuals planes or boats you know who you are), and setting up nieces and nephews for college, there would still be plenty left over. A few years ago I thought what I'd like to do is set up a foundation that would build modest public observatories around the country.
There it is out on the table. So after I win it big, you can rightly bother me by asking, "So what about are those observatories you promised?"
And what would you do?
March 3rd update: No winner, again. Tuesday's jackpot is now more than one-third of a billion dollars.