The BetaCells in Diabetes site uses podcasts, blogs, a custom resource search, and case studies with voting to create a great resource for healthcare providers. This Drupal site also integrates with the PubMed system from the National Institutes of Health to provide state-of-the-art resources.
Psygon is an innovative new learning site where users can create and answer questions on a variety of subjects. The site uses Drupal 7 including Features and custom modules. There's even a patent-pending algorithm for selecting the best next question to ask a user.