Chatroom/shoutbox and Calendar
I just add a chatroom (shoutbox) and a our google calendar to the side bar.
It is only visible to logged in users. When you type a message in the chatroom it will be visible to all other logged in users.
That is our google calendar embeded into the sidebar. I chose the agenda view as opposed to the week/month to better use the narrow space.
Let me know if you like these changes or not. They take a little bit of room away, but I am hoping they will be useful. If it is really annoying to have them on the home page I could move them into their own dedicated page.