Hasin Hayder has posted part one of a series he's doing on making an application similar to the popular FriendFeed site in PHP.

Friendfeed is an excellent life streaming service aggregating all your feeds from different service providers, compile them together, build a social network among your known people and finally deliver all these feeds as a mashup. [...] In this blog post I will try to focus on how to develop such a service like Friendfeed using PHP and JS and how to scale such a huge load successfully.

This first part looks at the photo sharing handling of the application, including links to libraries already written in PHP to connect to them (like Flickr and Smugmug).