Kevin Kelly's got some great travel tips:
If you hire a driver, or use a taxi, offer to pay the driver to take you to visit their mother. They will ordinarily jump at the chance. They fulfill their filial duty and you will get easy entry into a local’s home, and a very high chance to taste some home cooking. Mother, driver, and you leave happy. This trick rarely fails.
I've done this with housekeepers in Cuba and the Dominican and got some great meals and conversation. Offer a local restaurant price and get a terrific home cooked meal.
If you detect slightly more people moving in one direction over another, follow them. If you keep following this “gradient” of human movement, you will eventually land on something interesting—a market, a parade, a birthday party, an outdoor dance, a festival.
It doesn't have to groups. I also follow interesting-looking people and have ended up at great restaurants, and once, in Spain, watched a religious parade that I would have otherwise completely missed.

Lots more on KK's site: 50 Years of Travel Tips.