Here's an interesting article on CNET that demonstrates how surfing the Internet helps stimulate the brains of middle-aged and older computer-savvy users. Looks like we can add one more weapon to the arsenal of fighting off senility in our later years. Activities like playing cards and doing word/number puzzles have been recommended for years. My guess is that things that make us actively USE our brain in order to participate, be it puzzles or web searches, help keep all those brain connections hopping and maybe even help develop new ones to handle the extra traffic. So if, God forbid, the connections start deteriorating over time, the additional connections we build up through using the brain actively will help offset at least some of the age-related loss.
So keep on surfing, Dear Readers! :) It's good for your brain!