The SitePoint PHP blog has a new tutorial posted today kicking off a series about creating a "social network style posting" application that combines PHP, MongoDB and jQuery that feels similar to a nested commenting system you'd see on most social sites.
Post mechanisms similar to Facebook are nowadays very common within any application. The concept of Post-Like-Comment is familiar to everyone who ever used a social network. In this article, we will learn how to create a similar working model wherein the user will be able to post his status, like posts and comment on them. What's more interesting is that after learning things from this article, going forward you will be able to implement a lot of other features on your own.
In this first part of the series they start you off with the base code and introduce you to how the data is stored. They also walk you through how the "stream" part of the code works and the tracking of the current user. From there, there's a brief look at how to pull out the comments and display them to the page.