Foursquare "Super Swarms" of 250 people or more are now so frequent that the location-based startup is rolling out new badges to award users who convene in more massive quantities.

Beginning today, when 500 or more Foursquare members are gathered together at the same venue (and checked in, of course), those users will be rewarded with a Super Duper Swarm badge. There's also an Epic Swarm badge to commemorate events where attendance on Foursquare pushes past the 1,000 mark.

"When we made the original Swarm badge we thought, 'What are the odds of ever getting 50 Foursquare users together?' And then we did the same with Super Swarm for SXSW. 'Will anyone ever even unlock these?'" explains Foursquare co-founder and CEO Dennis Crowley. "And now they are unlocked on a regular basis — baseball games, concerts etc. So we needed bigger."

So what happens when 500-and-1,000-person swarms become commonplace? That's a question even Foursquare is not prepared to answer. "In our internal badge meetings, we're thinking, 'What's after this?' We have no idea," says Crowley.

Though the badges themselves are pure novelty, they do represent the ballooning growth of Foursquare's user base and highlight just how much activity the startup is capable of generating around offline venues.