Yesterday, word came out that Facebook had been granted a patent that essentially made them out to be the inventors of "Systems and methods for automatically locating web-based social network members". This could obviously have a big effect on businesses like Foursquare and Gowalla and SCVNGR who are operating just such businesses.
This morning, Business Insider reports that actually Google already HAS a patent on pretty much the same thing with the head of Foursquare listed as the inventor.
Facebook Places is a huge priority for the company right now, Zuckerberg mentioned it prominently in his speech again yesterday. And the whole industry is kind of blowing up right now as companies try to wed cyberspace to meatspace.