A few weeks ago I wrote a blog post about an experiment I tried on Google+. It was not terribly scientific; I was curious to see how many people used the 'Nearby' stream that I noticed on the Google+ Android app so I posted a comment with a location asking for comments. I had not explicitly requested locations from the people reading it but some people volunteered this information and it became apparent that 'nearby' is a bit of a loose concept.
Recently, Google made accounts on Google+ available to everyone, having previously restricted it by requiring an invite from an existing user., and I was curious to see what this did for the 'nearby' range. To this end I put out another post with a location attached, this time asking people to tell me where they were reading it from. This time I had more individuals responding, as I expected with the increased population, although no conversations started this time so the total number of comments was much fewer. Here is a map of the results.
(View as a large map) The red marker is where Google+ thought I was at the time (I didn't have GPS turned on when I made the post so it is accurate to a few hundred meters). As I was watching the comments come in I thought that the range had been brought in but now looking at the map I see that there are still three outliers to the West at about the furthest distance I saw last time. Someone even commented that he was in New Zealand, but when I looked at his profile it contained almost no information and his comment vanished after a few minutes so I think it was someone having a laugh.
I don't know if this proves anything but I thought it was interesting.