Foursquare continues to sign interesting deals with major players in a wide range of fields. Following the service's Bravo deal a couple weeks ago, they've reached a deal with restaurant rating guide Zagat, according to The New York Times. And AdAge has some details about deals with even more partners, including HBO, Warner Brothers, and the History Channel. The service has been on a roll lately. They're now seeing over a million check-ins a week, with that rate doubling in the last month alone. And these new deals can only help them as they bring the type of mainstream appeal that it took services like Twitter so long to find.