Google released some eye-popping numbers today alongside its unveiling of Google+ Communities, the company's response to Facebook Groups. (Watch a demo of how it works below.) In a blog post, senior vice president Vic Gundotra says "Google+ is the fastest-growing network thingy ever" with more than 500 million people having signed up for the service. Surprisingly, 235 million of them are active users

I know what you're thinking: Isn't Google+ a ghost town? Who are these "active" folks?

According to Google's own tally, that 235 million figure includes anyone who +1s an app in Google Play (which recently forced once-anonymous users to sign in with their G+ accounts), uses a Hangout in Gmail (which are really fun!), or connects with friends using Search

As for how many of those users are in the Google+ stream itself (i.e., Google says it's more like 135 million.

That's "still an impressive number," says Chris Davis at SlashGear, "though [that's still] the minority in comparison to the more than 500 million who Gundotra says have upgraded their account." Josh Wolfrod at WebProNews notes that 135 million monthly active users hardly constitutes a "ghost town." Compared to the 100 million announced back in September, it means Google+ is "on a rough pace of 160 million new active users in a year."

Take a look at Google+'s new Communities feature: