For now, at least, Foursquare seems to be doing gangbusters, and the service apparently has Facebook Places to thank.

Wednesday's was heralded by many as the .

Sure, Mark Zuckerberg invited Holger Luedorf, Foursquare's vice president of mobile products, on stage during the event, and Luedorf said Places "validated" the space that his company had worked so hard to legitimize. But many pundits insisted that the entry of a juggernaut like Facebook into the space will inevitably eliminate all room for competition.

For now, at least, Foursquare seems to be doing gangbusters, and the service apparently has Facebook Places to thank, according to Foursquare co-founder Dennis Crowley. "Just heard from [Foursquare head Harry Heymann] that today was @foursquare's biggest day ever in terms of new user signups," Crowley tweeted.

At least for the time being, Foursquare seems to reaping the benefits of Placesor, at the very least, the higher profile that the event afforded the company. Also, keep in mind that Facebook used the occasion to announce that it will be opening its API to third-party companies. Foursquare and fellow location-based service Gowalla were among the early announced partners for the new service.

According to Crowley, Foursquare is now well on its way to three million users. So, should Foursquare still be worried? Well, according to our editor-in-chief Lance Ulanoff in yesterday's column, "Facebook Places Will Crush Foursquare"well, the answer's kind of in the title, isn't it?