I like candy. Whenever I travel I like to eat fun, delicious foreign candy...this typically brings me to the local grocery or convenience store, which, my friend, if you are traveling, is where you need to be too.
It started a few years ago while in Switzerland. A local suggested the best place to buy real Swiss chocolate (the kind you can't find in the States) was at the grocery store; she said the price and selection would be better, since supermarkets typically cater to locals (rather than tourists). Actually, scratch that, my love for stopping at local grocery stores may have began before that while in Costa Rica, wandering around San Jose looking for snacks and pottery (and at that supermarket I got a great pair of rainbow flip-flops--that I still wear--for about $1 US).
Then, while living in Germany, I was constantly finding yummy new candy which I had to share, so I was always sending my friends and family different treats. (like Kinder Eggs). This evolved into my sister and I swapping candy whenever we travel.
Sometimes, on the road the most boring tasks--like grocery shopping--can become some of the most memorable and culturally educational events. You can discover local sauces or even regional differences in popular or familiar foods. Like, in Hawaii you can find Spam musubi (Spam atop of bed of rice and wrapped in seaweed) at local 7-11 convenience stores. And, though many counties have KitKat candies, the flavors, like cappuccino, green tea, white chocolate, or strawberry tend to be regional. These are great (and inexpensive) gifts to bring back to friends at home, who, like me, like candy.
I guess what I'm trying to say in a round-about way, is that if you really want to eat local or learn about a culture, hit up a grocery store--you will be greeted with exciting smells and tastes, along with a wonderful blend of the familiar and mundane with the exotic and adventurous.