WP Symposium, yes with this free you can create a full WordPress powered moduleSocial Networking site easy and fast just install and set some configurations and you are good to go. you can even decide not to have some of the features available and just disable them.
Users of your site can using their Profile Wall, Post their status, post on their friends wall, reply to them and even make them private.
They can request friendship, accept or reject it, send email to them and also check their status.
They can upload the image and then crop it on the website and post it everywhere on the site(just imagine how long would it take you to write just this part)
They can set their personal information on the site, set preferences for privacy, You can have custom fields to your site and also Automatically adding google map to the site.You can create a forum on your site that will allow you to setup categories, generate daily digests, create favorites, Search the posts and view your activity, share it with Twitter, Facebook, Linked-In and more.., also you can send email notifications, set the post sticky and Disallow replies.
You can setup a panel on your pages that will allow you to see Notifications like New mail or friend requests, See friends online, Have a private chat window and even chat site wide and you get all the new emails with highlights!
You can have widgets to setup polls of yes/no votes, New members widget or recent posts to the forum.
You can even request more features from them.