relational aesthetics

The reading relational aesthetics has an interesting premise: that contemporary art can engage people by forming a kind of mini community that occurs as people happen to experience that art together. I agree that watching an installation is different from watching a movie.
Thinking of that, however, made me think about the opposite, where two people might inhabit the same room physically but are in completely different spaces through the use of electronic devices such as ipods, cell phones or blackberries. Every day when I take the subway, even in a very overcrowded train, people situate themselves as to create more space for themselves. In fact it is rude if someone looks at another person deliberately or an extended period of time. Occasionally, there are people who might break these social conventions, such as young children, or some unusual adults. However, there are still unspoken codes for appropriate behaviour that people seem to follow.
Bourriaud's raeding about art that can start a conversation between people is a good one, however, I wonder in the context of everyday museums and galleries, where there are still, "look, don't touch" policies, how it can be applied so there is more engagement between people.