Popular image-sharing application mlkshk now has a mlkshk API for building mlkshk-enabled applications. The service provides a social image discovery and sharing technology, with a RESTful API allowing access to a user's mlkshk account, friends, favorites, and personal image collections also known as "shakes."
Most people don't realize how many popular photo services like Flickr, Smugmug and Picasa offer web APIs. In this overview, we'll take a look at the breadth and power of currently available photo APIs and the types of photo mashups developers are building with them.
Popular iPhone photo-sharing app Instagram is a prime candidate for an API, which is probably why it already has one. Though documentation refers to it as an "unofficial" Instagram API, the fact that it uses the company's own servers makes it seem pretty official. Instagram has not launched the API, nor is an API linked from its home page. Yet, it has a mobile app and right column Twitter integration, both of which likely consume the API.