Class Connect. Since then Class Connect's founder Eric Simons has taken the service through some re-engineering and rebranding and has now re-launched his service as Claco.
Claco is part online filing and part social networking. Using Claco you can collect and organize resources into binders. The social networking piece of Claco allows you to subscribe to other members' updates. When you subscribe to other members who have made their binders public, you can quickly "snap" their shared resources into your own binders. For example, in the screen capture below you will see that I am "snapping" one of Steve Spangler's shared resources into one of my binders.
Applications for Education
Claco could be a good place to organize your lesson materials and share some or all of them with other educators. If you're looking for a place to find new lesson ideas and resources, take a look at Claco.