Like most people with a digital camera, I tend to be a heavy Flickr user. Not only does Flickr make it easy to share my ever-growing photo collection with colleagues and family, but its drag-and-drop photo organizer and geo-tagging features make it easy to quickly categorize and find pictures from, say, my 2003 holiday in Goa.
The really good stuff, though, is hidden behind the scenes. Like many Web 2.0 applications, Flickr exposes its data to the public via a REST API, making it possible to develop customized applications that run on top of the base service. This REST API allows access to a number of important functions, including photo searching, tagging and uploading; photoset retrieval; contact retrieval; and panda recommendations. It’s also pretty easy to integrate this REST API into a PHP application – and this article will show you how!

