Who says that you always have to use the camera straight on, with the eyes aligned perfectly with the lens? Experience would tell you to look for different, perhaps better angles to get that shot you're looking for. hippopo0838 for instance, loves the stories behind his subject's backs!
I love to take the pics of people’s back rather than their front. Of course, it was not because they weren’t good-looking. Rather, finding meaning behind the photos of their backs are more intriguing for me. We may tell the emotion of a person through their facial expression. But their actions can show it as well. For example, Jumping may mean happy; looking ahead means thinking; looking down may mean blues. Without the expression, you will take more consideration of the motions they are making.
Most of people are still not used to face the camera head-on. They may act unnaturally and look at you all the time, or they just walk away quickly. Of course, we need to respect the person who doesn’t want their photo taken. But, why don’t you just do it other way, taking the photo of their back?
Without the camera faced directly, people won’t feel tense at all. Even if they know that you were taking a picture of them, the posture doing will be more relax and genuine. I like to step in the crowd and watch the people do their thing and get some photos of them. Those pics of the back are always beautiful and meaningful. Are you thinking the same way as I am?