It is probably old news to most, but I just stumbled across Groove that came with our Office Enterprise installation. It seems like a modified version of sharepoint, where you can create workspaces that are able to share documents, calendars, discussions, etc. What is really nice is 
that you dont have to run a server to do it. Each person in the workspace has an encrypted copy of the workspace locally on their computer. This means that even if you are “offline” you can still edit documents, etc on the workspace, and as soon as you get back on the internet, encrypted changes are sent out to everyone that is a member.
They have a “server” version of this for very large organizations as well as an “enterprise services” version that lets you have finer control over who can do what, but for a smaller than 500 user organization, the regular groove service should be just fine. So, quit sending out multiple copies via email, just create a workspace! Here are a few links to look at…
Modmaven's Weblog 