Chat
Start communicating! Bring live two-way chat to your site. Host your own live chat sessions, interact with your visitors and increase sales without JavaScript third party or other code - works great with BuddyPress and several sites as well.
Goodies Twitter
Official Tweet Twitter Profile button + extras and search Widget. Plugin shows your tweets on page Post / Widget area.
Skype Online Status
The plug-in for Skype Online Status allows you to add one or multiple, highly customizable and accessible (!) Skype buttons to your blog. You can choose any of the available themes Skype button to show their online status and place in its pages and content of the messages (with a neat little button on the Skype quicktag WYSIWYG editor) in the sidebar through widgets (unlimited) or any place on file the theme of the template.
Manager tab Facebook
WordPress ago served as editor of tags can be embedded in a Facebook page for your company, campaign or organization.
Private BuddyPress Community
This plugin makes your private BuddyPress community. Only logged in members can see the social areas in their entirety. You can configure the default settings.
FV Community News
Give your site visitors the ability to send their news to you, and the list in a pleasant news service.
Open Alkivia Community
A plugin to build communities of users around WordPress, it's mostly about having a well integrated system profiles. This plugin provides all the necessary functions and widgets for easy and flexible ways to display all the information about a user. Furthermore, some user privacy settings to allow information to be displayed in the profile page.
Disqus comment system
Disqus, pronounced "discuss", is a service and a tool for web comments and discussions. Disqus makes comments easier and more interactive, while connecting websites and commenters across a thriving discussion community.
WordPress advanced ticketing system
This WordPress plugin adds to the characteristics of a complete ticketing system. This allows users to send entries to report problems or get support in whatever you want. Users can set the status, priority, product and type of each ticket.
WordPress Bar
DiggBar seen on Digg.com? Add a function similar to your WordPress blog by creating a navigation bar for all external links outside of the blog.