RSS feeds are not officially supported by Google Plus
yet. that's bad if you want to follow a specific user on the new social networking site. Sure, you could add the user to a circle to read all (public) messages on the Google Plus website, or visit the stream of that user directly to access the new messages.
Both options are not really that comfortable, especially if you do not hang out 24/7 on Google Plus. The alternative? You could try a service that turns a stream into an RSS feed.
Google Plus Feed is such a service. It is hosted on Appspot and provides barely any information, so take it with a grain of salt. Could be gone before you can blink with the eye.
It is fortunately dead easy to create an RSS feed for a Google Plus profile. All you need is the user's Google profile ID and the url that you have to add it to to create the feed.
Just visit a user's Google Profile on Google Plus to get the ID. You find it in the web address of that page, it is the only number there. I have highlighted the ID for you in the screenshot below.
The ID is also listed on your stream. Each user name is linking directly to the profile of that user. To get the id right-click on the name and select copy link location.
Now that you have got the ID you need to add it to the following url:
Removed, no longer working. Check updates below.
Just add it at the end and load the page. You get an RSS feed that you can subscribe to in your RSS feed reader of choice.
You can repeat the process for additional Google profile RSS feeds if you like. It it likely that Google plans to add RSS capabilities to the profile natively. For now, Plusfeed offers a fast way of creating feeds for Google Profiles.
Update: The Google Plus RSS Feeds service has been shut down by its developer. You find an alternative here: Use Dapper To Create RSS Feeds From Any Page, Including Google Plus Posts
Update 2: Plus Feeds is available under a different url again, you can access it here. Thanks Kim for letting me know about it.
Update 3: The second Plus Feed address has been disabled as well.
Update 4: Use Google+ User Feed instead which works fine at the time of writing. All you need to do is enter the user ID and click the get feed button to get the feed for that channel.