This is another cool, free plugin that will allow you to build a superior social network site – just by using WordPress.
When you use WP Mingle, your users won’t see the Admin part or the WordPress login screen; it’ll look like a separate, non-WordPress social networking site.
Awesome Features Of The WP Mingle Plugin
You can comment and create profile posts on friends profiles
You have the ability to opt in or out of user email notifications
Users will be able to upload custom avatars (Gravatar fallback is also present)
There are pages for friend activity
Pages are also available for user friending
By using @ followed by the name of the user, users on your WordPress social network site will be able to tag each other – Twitter style
As the admin, you’ll be able to configure custom profile fields and also user profile pages
Your WordPress social network site will have a registration system, a lost password recovery system, a login and logout system and these will all be at the front end
There’s a facility for users to indulge in private messaging
There are random and recent users widgets, plus login and navigation widgets
There are Pretty Profile URLs (this will help with Google Indexing as well as with memorability.