I have some code in PHP that I’m tinkering with. The original idea came from http://plusfeed.appspot.com/.
You can view the progress: https://techish.net/pub/googleplus_rss.php
You can use ?id= to supply your own Google+ ID string found when you login and navigate to http://plus.google.com/
The string of interest here is:
XXX is your Google+ ID.
[update: August 7, 2011 22:45 EST]
The RSS is for the most part complete; I have some code clean-up to work on yet but it is working. Check out the right column and you’ll see my public feed from Google+.
To reference this, simply add: https://techish.net/pub/googleplus_rss.php?id=YOURGOOGLEPLUSIDHERE to the RSS widget source in WordPress – or in your favorite RSS reader. Let me know if you have any problems!
Tip: You can show the latest N by adding ?latest=X to the URI.
[update: August 6, 2011 02:07 EST]
I have completed most of the work. I’ve added two user controllable parameters:
id - Integer: Google+ ID latest - Integer: Latest X number of entries to return.
https://techish.net/pub/googleplus_rss.php?latest=5 will show you my latest 5 entries.
I plan to add date constraints sometime soon and eventually I can maybe pull in comments to the entries(?).