Back in February 2010 we asked Why can't you share photos on Foursquare? We discussed that this could be seen as an oversight or an opportunity for others. However, this question has now been deprecated by Foursquare with the introduction of its add photo API method, which suggests that the previous absence of a method was simply because it wasn't a priority, it was an oversight or the opportunity hasn't been taken up by developers as Foursquare had hoped. In addition to the new add photo method, Foursquare have also introduced API methods which allow comments to be added and deleted from checkins. These methods have already been rolled into the official iPhone and Android apps along with a few 3rd party apps that use the Foursquare API.
In October Google announced the cost for Google Maps if you use above 25,000 map loads per day. Many developers balked at paying for a service that had been free for several years, though it affected fewer than 1% of developers using the Google Maps API. Now the search giant is lowering the cost from $4-8 CPM to a fixed price of $0.50 per 1,000 map views. It will also start enforcing the price, though the company says this process is not automated.
Rap enthusiasm site, Rap Genius has gone through the impressive tasks of combing rap and Google Maps. Rap Genius' Rap Map is a Google Map-based visual almanac of all things rap. You can scan an area and view rap landmarks and places mentioned or referenced in some famous rap lyrics.