Facebook is by far the most popular social networking site on the web. If you are a web application developer, chances are you have tried to use the Facebook API at least once. While the Facebook developer platform offers Facebook Connect and Client Libraries for various languages, including PHP, Javascript, ASP.NET, and Actionscript, these libraries are, in my opinion, rather hefty.
In one of my recent projects, I wanted to allow my client and server code to interface with Facebook "directly". Of course, one should avoid hardcoding the Facebook App API Key into the client code, and one should NEVER transmit the Facebook App Secret to the client side at all. Therefore, any client calls to the Facebook API should be passed through a server.