The Project Diary can be used as a running log of project activity. Use it to keep track of the notes from your regular status meetings, ask your account/project leads to create a new entry every day, or use it as a "production log." The project diary is the perfect place for new team members to go to get up to speed quickly.
Every entry can contain an unlimited amount of vital data. The diary edit screen is extremely easy to use, and easy to add things like HTML markup, etc.