Many of my posts are public and even have a geo-tag. I already found interesting people by using this feature when either they commented on my posts our vice versa. I think it's a great way to discover interesting comments and people. Though you won't find me nearby, me being in germany.
I don't tend to geo-tag because I've haven't really figured out what the point is. Check-ins yes, photos- fine and obvious as well, but my location has nothing to do with most other posts.
What I would like is the ability to post ONLY to nearby people. That way I can post about local issues without bothering people on the other side of the country who might follow my public stream.
+Steve Kunzer , do you use the g+ mobile web app, the iOS or the android app? They might differ in functionality as they are do not receive updates at the same time due to OS differences.
+Steve Kunzer, which mobile interface are you using? You can certainly geo-tag posts from the Android app'; though as you may be able to tell from this comment, '+' links to profiles are still, sadly, unavailable.
+Steve Kunzer, you are quite right about comments. I imagine that particular lack of function is by design, in the same way that you cannot embed pictures or video in comments. Whether you should be able to do so is another question, of course.
I don't geo-tag because I don't think people would really care where I post from, or I don't want to put a pin on the head of my house.
It also makes me think that very few people in the UK are posting to G+ from a mobile.