Google Buzz is a new service that takes aim at Facebook and Twitter by providing the ability to post links, photos and status updates directly from your Gmail account. And right off the bat Google has released the accompanying API.
Foursquare, the leading location-based social tool, announced a major new initiative last week to expand its location database to include cross-references to corresponding venue listings from other services. As characterized in the announcement post on the company blog, the goal is to make Foursquare the missing "Rosetta Stone for location, allowing you to link information about a real-world place from one database to any other." Now it's not just about using Foursquare, but connecting it to other services.