Google+ just rolled out its Ignore feature. It's less offensive than the current Google+ Block, which denies a person from commenting on anything the blocker posts. That lets people easily figure out you blocked them. You don't want that! Here's how to use Google + Ignore, which leaves no such clues.
Log into your Google+ account. From the Google+ bar click on Notifications. Then, from the list, click the Ignore link next to the person you no longer want to see in your feed.
Change your mind? Just click Undo.
To ignore all of the people on the list, click Ignore All.
Effectively, this lets you batch-ignore people.
If you want to add back a person, go to your Circles page. From the More Actions dropdown, click View Ignored.
A window pops up with a list of everyone you're ignoring. Click Unignore. Click Done.
The Ignore feature is available all around Google+--you also can access it from your Circles or Incoming pages.
After you ignore people, you'll no longer see their posts or activities. You won't see them in your Circles, either. This differs from the Google + Block feature, which still exists, by the way. Unlike Block, Ignore lets the people you ignore still see YOUR stream and post to it. You just won't have to see the posts.
The coolest part of this feature is the person you ignore won't have any idea you put them on the Ignore list. Or so it appears so far in my current Google + beta release.
For a full and in-depth explanation of Google+ Ignore and how it compares to Block, check out this video from two Google+ engineers.