It's a simple, but useful feature. Google just announced the addition of hashtag autocomplete to Google+. It's pretty self-explanatory. When you start typing a hashtag, it will suggest options as you type.
Here's a quick clip demoing the functionality:
From current events (#SOPA) to the arts (#MonochromeMonday and all those photo tags ), +#hashtags are a great way to build communities around content on Google+.
We want to make it even easier to use and discover hashtags, so today we're rolling out a new auto-complete feature. Now when you start typing a hashtag in a post or comment, Google+ will present a list of hashtags you might be looking for.
Did you know +Chris Messina is the godfather of +#hashtags? No doubt he would be the guy to introduce us all to a new feature rolling out now, to help you share the right hashtags trending inside Google+. Now you'll know more about #SOPA and #MusicMonday or #Caturday than you ever expected.
It will be interesting to see if these make their way into Google's web search suggestions the way other Google+ content has.