Live Chat by cSupport is a plugin that implements an inline Live Chat button to the bottom right of your WordPress site.
Live Chat features include:
No client software to download
Service live chats from any browser, including smart phones
Service multiple visitors simultaneously
Canned responses (pre-configured text added to a chat with a single click or short-code)
Includes a contact form when you are not available/online to serve chats
Google Talk Integration to chat with your website visitors directly from your google talk client
Reliable and secure
Complete chat history available for visitors and for the website administrator
The live chat service is provided by csupporthq.com. See http://www.csupporthq.com for a full list of features.
This plugin requires a cSupport Live Chat account. You can signup at csupporthq.com/pricing
Download: http://wordpress.org/extend/plugins/csupport-live-chat/
