Contacts Manager Program for Administrators


Is there a program or add-on template that would allow (only) administrators of our website can use - like a private to-do list and where we (the admins) can share ideas and thoughts with each other?

Also -- one that we can use and be able to store on our server. We currently are using 37Signals, but would like to be able to move from this to a Contacts Manager on our server/forum area.