Not quite two years ago in this space I wrote about how I use foursquare. I've continued using the service since then, passing 1,000 checkins several months ago.
The first generation of location based services like foursquare have paid a lot of attention to privacy concerns. Explicit connection to other users is required in order to allow them to see your checkins. To do otherwise would have been perceived as creepy, the go-to label for vague privacy concerns. For those who do want to make their checkins public, Foursquare has an option to publish checkins to Twitter.
Yet social norms evolve, even in the span of just two years. Facebook Places and Google+ both offer checkins as a feature of their respective services. I've been periodically checking in on Google+ for several months. For routine trips I check in to a very limited circle of people, not so much out of concern about privacy as to not be spammy. For well-known venues I've been checking in publicly, and something fascinating happens: well-known venues are really well-known. Lots of people have been there, and they chime in with commentary and suggestions of things to see and do. Our trip to the Monterey Bay Aquarium was much improved by real-time suggestions from Google+ users, and pictures from the trip in turn made a couple other people think about going back.
Jeff Jarvis has long made the argument about the benefits of publicness, and that overemphasizing concerns about privacy undermines the benefits we could get by being connected. We use nebulous terms in justifying privacy like creepy, and stifle discussion of the value of openness. Our brains are really good at concocting (unlikely) scenarios of the bad things which could happen from sharing information, and not so good at seeing the good which can come of it. I'm definitely seeing that effect with public checkins, it seems scary but yet there is tremendous value in sharing them widely.
footnote: this blog contains articles on a range of topics. If you want more posts like this, I suggest the social label.