I've got some good news and some bad news. First, the good: According to Dr. Aubrey de Grey, a geneticist at the University of Cambridge, "The first person to live to 1,000 might be 60 already."

I know it sounds outlandish, and maybe it is. Maybe for the foreseeable millennia, we'll top out around 500 years of age. Still, that's pretty impressive. I can imagine all kinds of upsides:

  • Soap opera fans will be able to watch events unfold on The Days of Our Lives for a long time.
  • We'll find out just how small and powerful semiconductor chips can get. Intel (NASDAQ:INTC) has recently developed a 45-nanometer chip, with more than 1 billion transistors on it. And by the way, a nanometer is a billionth of a meter.
  • We'll get to watch not only our children grow up, but their children, and their grandchildren, and their great-great-great-great grandchildren, too.
  • We'll watch super-sizing trends come and go at fast-food franchises and may bear witness to an outfit like Wendy's (NYSE:WEN) introducing a 3-gallon "superslurp" soft-drink size.
  • Now that Apple (NASDAQ:AAPL) has triumphed over the Beatles in its right to use the apple as its logo in promoting music products, perhaps we'll live to see the day when Apple the company triumphs over apple the fruit. Maybe Macintoshes, Fujis, and Granny Smiths will have to go by names other than "apple."

I could go on (this is fun), but let's switch now to a big downside of living so long: Your retirement savings could run out! That's right. Most of us don't have enough saved anyway, so having to stretch out our dollars for 935 years instead of 25 years can make a big difference in the style in which you retire.

Fortunately, all is not lost. Take advantage of a free trial of our Rule Your Retirement newsletter service, and let Robert Brokamp teach you how to design a nest egg that can theoretically last forever, thanks to conservative annual withdrawals.

There's a rosy corollary to all of this, too. The longer you live, the more your money can grow -- both for yourself and for your loved ones. Best Buy (NYSE:BBY), for example, has rewarded shareholders by an average of 38% annually between 1995 and 2005. If it keeps that up for just the next 50 years, you could turn $1,000 into nearly $10 billion. But high returns like that -- and like Starbucks' (NASDAQ:SBUX) 28% in the same period -- don't remain sustainable for too long. So let's be much more conservative and say that you earn a modest 5% return annually for the next 400 years. That's enough to turn $1,000 into $300 billion. See? When you're dealing with long time periods, you don't need blockbuster annual returns.

If you think you might be one of the 500-year-old or 1,000-year-old people of tomorrow, consider socking away some money for your children, grandchildren, great-grandchildren, and other descendants. Imagine how happy you'd be today to learn that 100 years ago your great-great-grandparents socked away $500 for you. Growing at 10% annually, it would have become nearly $7 million. Let the power of time work for you. You can actually do more for your distant descendants now than you can for your immediate ones, with just a little money or a few shares of companies with long-term promise.

Plan for your retirement, and make sure you're saving and investing enough for it. Consider taking advantage of our inexpensive TMF Money Advisor service, which offers personal, one-on-one consultations. Or just let us help you find an advisor.

And in the meantime, be nice to people and brush your teeth regularly. You don't need to end up with a mortal enemy for 800 more years -- or dentures for 600 years.

Longtime Fool contributor Selena Maranjian does not own shares of any companies mentioned in this article.