Just a quick note worth mentioning: Microsoft has just released the downloadable version of the OCS 2007 R2 Product Documentation in the Complied Help Module (.chm) format. Anyone with a previous TAP/RDP version of the file from Connect should replace their with this updated copy as there are many new sections (the overall file size has nearly doubled) and appears to now match the online documentation.
You can download the Communications_Server_2007_R2_Documentation.chm file here: