Okay, I might be exaggerating a little bit. But a new study  has shown that the "average dog can count, reason and recognize words and gestures on par with a human two-year-old." I think the increasing popularity of dog sports and interactive games, such as the Tug-A-Jug  and Nina Ottosson's puzzles  demonstrate that we're doing a better job of exercising our dogs' minds as well as their bodies.
Back in the day, dogs were bred for a certain job and that kept them physically and mentally fit. Now most family pets live a life of luxury - eating the best food, sleeping on the softest bed - but don't use their brains after completing Obedience 101. I keep my dogs mentally active by participating in dog sports and teaching them tricks using the clicker. If you want some ideas, check out these great trick-training videos  of Rounder the rescue Rhodesian Ridgeback.
How do you encourage your dog to use his brain?