One of the biggest obstacles to comfortable street sociability among strangers in the US is the pervasive and damaging street harassment women endure on a daily basis. This culture teaches women that it isn't safe to interact, and it teaches well-intentioned men that it isn’t acceptable for them to speak to women in public. Hollaback is a great organization fighting the harassment of women in public and online. You can participate in two ways. Donate to support their work, and share your own experiences on their website.