GroupLoop
http://www.grouploop.com
Keep your group in the loop with this application. GroupLoop provides a simple place for you to share and archive files, a central area for discussion, and a calendar to manage your meetings.
I have had a chance to test-drive the application ahead of time, and it looked very solid with fast loading pages and impressive interface. Flexibility and ease of use are the key ingredients of GroupLoop, looking to publicly launch the service sometime soon.
GroupLoop is a great substitute to email coordination, and I find it will do especially well among small to medium-sized teams. Since it's Web-based, you can access it from anywhere.