Been having fun lately experimenting with Elgg: the learning landscape, a social networking tool created for use in education. It's a lot like Orkut. Each user

• gets a blog
• has a file upload area for sharing files
• can offer extensive user profile data
• can create friend networks (like in Orkut)
• can create communities which have their own blogs and membership listings

Furthermore, elgg allows for freetagging all sorts of content and has an RSS feed for almost every type of content listing imaginable. And the file uploads, individual weblog posts, community weblog posts, and even profile data all allow for varying degrees of public and private access. Users can even create their own groups (from among their friends) and use them to control who can access content.

Note that you can register on elgg.net and create your own profile and join in the communities there. Or, it is open source software that is fairly easy to install for anyone that wanted to setup an elgg site in their department or institution.

I like this as much as I like Drupal. Elgg is about as different from Drupal as each of them are different (in their increased feature set) from regular blog software such as WordPress or MT. Definitely worth a look see before setting up those old boring individual weblogs for your class. This is a whole lot more fun.