Note: PlusFeed is not affiliated with Google or dlvr.it. Google does not officially support atom feeds of Google+ posts. Accordingly, the operation of PlusFeed Google+ feeds is subject to change without notice.
Update 9/7/11: PlusFeed has announced they are ceasing operations. However, dlvr.it will continue to support existing plusfeed.appspot.com feeds without interruption. We are running our own instance of plusfeed and are redirecting all plusfeed.appspot.com queries to live dlvritplus.appspot.com feeds.
2. Publish your Google+ posts to Twitter and Facebook using dlvr.it
a) Go to dlvr.it and create an account with your email + password.
b) Enter your Google+ feed URL from step 1 above
c) Click on the Twitter icon and authorize dlvr.it to post to your twitter account.
Click "Authorize App" in the Twitter Authorize an App page:
dlvr.it will now automatically post your new Google+ posts to your Twitter account. Posts will link back to your Google+ posts at plus.google.com.
d) To post your Google+ posts to Facebook, click on the '+ add' button
e) Choose Facebook from the dlvr.it Destinations list
f) Follow the Facebook authorization process and authorize dlvr.it to post to Facebook
dlvr.it will now automatically post your new Google+ posts to your Facebook account, too!
Your finished route will look like this:
This post was inspired by a related post on Chrome Life.