I find the holla back nyc site linked above very interesting for a variety of reasons. I believe I got there from this article on Salon.com, where they point out some of the benefits and drawbacks to this sort of thing, but it is a nice intersection of community-building, alleviating the isolation of being stared at/heckled/objectified in public spaces, and the use of the cameraphone for panoptic policing in the hands of those who normally don't have much say in what happens when heckling begins.
In India they call this behavior "eve-teasing" and as in the US, it's not just innocent fun or words or even threats with no physical consequences. It's about fear and the inability even to go to a museum without being chased through it "just to talk." It reminds me of a rather cathartic talk session I had once with four other women who study India--we were in a cab sharing our worst "grope stories" from our research days. Not one of us didn't have one, and some were much worse than I had experienced. But of course it doesn't need to cross the line into physical contact directly--it all affects your physical being, your ability to move around, to dress a certain way (although I found that it didn't matter how baggy my trousers were or how potato-sack-like my tunic was, they still stared), your blood pressure, your psychological well-being.
It also reminded me of an afternoon session on protecting oneself from physical assault run by IMPACT that involved teaching women (and they have some courses for men--the gendered nature of self-defense courses is a bit of a problem) what to do and what not to do in situations where you do feel threatened and thus are threatened. One of the women in the group was younger (high school) and so would talk back in situations rather than attempting to extricate herself. It was interesting because I completely get her feeling of wanting to take back the power by talking back, wanting to rise to the heckles, act like a man, but she ended up putting herself in a more vulnerable position by answering, revealing things about herself, her plans for the night, whatever it was, that then the heckler-cum-attacker used against her. So this hollaback site seems to be a good thing to me. shame a few people, perhaps. not give anything away except that you have a cell phone (and could call someone or the police) and you've taken their picture (thus recording their face for any future legal action).
I can recommend IMPACT to anyone in a city where they do courses--even the few hours I spent there gave me a good sense of what instincts to trust and what not to trust in a threatening situation. The main thing I took away from my short course was the ability to speak the word "No" and have it be heard. They teach you how to break through your politeness training into a forceful verbal negative. In other words, they make girls learn how to shout, once and for all. How great is that?
It would be a great world in which hollaback and IMPACT didn't have to exist, and yet. and yet.