Popular social check-in service Foursquare is going through some changes, and the most important of those is that the old v1 API is going dead, as we've known since March. Older apps, especially abandoned ones, will stop working then, as will any newer app that hasn't yet upgraded to the new API.
Google Chart Tools is the search giant's bundling of the Google Chart API and Google Visualization API. These tools create the perfect means for businesses and students to visualize data on websites as well as other types of presentations.
Want new APIs? This week saw an interesting mix of new entries in our API directory including a service for publishing and accessing location-relevant content, a simple API to get a JSON-formatted list of people you tweet most, a variety of APIs based on Clickatell's SMS services, a video API providing search to over 300 million online videos, and a real estate listing search API for Multiple Listing Service (MLS) properties.