Sponge's Shoutbox Web Part is a simple implementation of the popular "Shoutbox". It allows users to interact with each other without leaving SharePoint.
Sponge Features
Edit Page
button --> Add a Web Part --> Sponge Web Parts --> Shoutbox Web Part.
That's it. Now enter your text in the textbox and click the Send
button.
The Shoutbox Web Part stores all information in the Sponge Shoutbox
list. This list is relative to the web part (in the same SPWeb) and it will be automatically created if it does not exist. Be aware, that depending on the usage of
the Shoutbox Web Part, this list may contain thousands of items.