"Yahoo!" has a wonderful article about Bernice Gordon, a cruciverbalist who has recently turned 100. Go read it, it's fun!
I don't know if I'll reach 100, but if I do, I would love to still be constructing crosswords at that age (and hopefully continuing to publish them at World of Crosswords!).
On a related note: some studies say it's possible that doing the crossword on a regular basis can prevent diseases of the brain like Alzheimer's (article in the Daily Express). Unfortunately, some neuroscientists, such as Nicholas Spitzer, disagree (article in The Economist). As usual, there are no guarantees... but it's pretty clear that doing the crossword does develop your vocabulary and expose you to interesting facts that you might not see otherwise. Plus, they're just fun - which is the main reason to do them!
