Use QB Group Chat Room (XMPP)! Be social!
QB Group Chat Room (XMPP) is a simple plugin for WordPress that adds a Group Chat Room widget to your website.
Plugins Official Website: http://chatroom.quickblox.com
Plugin doesn't work for some reason? Use QB Group Chat Room HTML code generator. It is universal and works with any website / web app.
Cross-platform feature: QuickBlox allows your web visitors communicate with your mobile app users. If you have an iOS/Android/WP7/Blackberry app or want to build one, download QB Chat Room code mashups from http://quickblox.com/developers put same app ID as you have in your WordPress widget and enjoy your user base united.