The message board allows all members of a project to comment and share info about activities, but to use this feature there a couple of things to keep in mind:
1. You must be assigned to the project and have access to the activity, to post a message to either.
2. If you want to add a message to an activity you must choose activity name, before you can post a message.

The EP online help file covers using the message board in great detail, and can be found at:
http://www.easyprojects.net/easyprojects.net/Help/message_board.htmArticle ID: 54, Created On: 7/3/2008, Modified: 10/26/2011