OIT has published the Summer 2007 "Most Active Blackboard Courses" reports for all categories of usage (e.g., all courses, graduate courses, undergraduate courses, communities, etc.).
In addition, we have published the specific "tool usage" metrics for the top 50 courses in all categories. Future plans include providing this for all courses.
Reminder: Course activity alone is not a measure or endorsement of quality. These reports are merely provided as a way for faculty to seek each other out about what works (or doesn't) in using Blackboard.