
RSS feed is one solution for this problem. RSS is most popular option for get latest updates from any website or blog on internet and we can used it to follow a specific user on the new social networking site also. But unfortunately RSS feeds are not officially supported by Google+ yet. That's bad of course.
RSS feed subscribe option is still on the process of developing Google+ project with another service like API, media player plug in and everything in between. But we can try a service that turns a stream into an RSS feed using third party applications.