Great thread. I am always looking for ways to do this when I travel. I find walking around neighborhoods most rewarding. On my last trip, I stayed in a fishing village turned resort town in Holland. The big luxury hotel on the beach was surrounded by big restaurants, but I wanted to find the places where I thought the locals went. So I walked away from the beach and around a neighborhood where I found a wonderful Indonesian restaurant one evening. On another, I found a lovely French place. All around me were Dutch people, out with their families or friends. On the weekend I went to a pancake house in a park that looked like a popular place. I tried my few phrases of Dutch on the waiter, and a Dutch couple dining next to me asked where I was from and when I said I'd only been there a couple of days, exclaimed, "You've only been here two days and you speak Dutch?" We had a nice chat. It's definitely easier to meet people when you're traveling alone, but finding people is easy if you're willing to walk just a little distance away from the tourist centers. And just trying a few phrases of the locals' language (even "I don't understand") can open so many doors to great experiences.

Travel alone! I have traveled many ways, but when I'm on my own is when I really get to know the locals--they talk to you and invite you to join in. Also, travel off-season, stay in smaller accommodations, eat where locals do, learn a few phrases, shop where locals do, use public transport, walk in real neighborhoods, and if possible stay long enough to get the rhythm of the place. Also, discover the places that have yet to be overrun with tourists: The villages above the coastal roads, the smaller, out-of-the-way Greek islands, the Eastern European countries. My greatest joy in travel is feeling a part of the "real" scene.