OCS APIs
If you haven't seen them before the following OCS API's are now available
http://blogs.msdn.com/jcalev/archive/2007/05/07/introduction-to-the-ucma-api-part-1-api-overview.aspx
They are detailed on Joe Calev's blog very well and it explains exactly what you can and cannot do with them.
So if you are a developer and want to get creating cool stuff for OCS and Communicator I guess this is your starting point
