I'll get this linked on the rings page next week--

Rings are private feeds (similar to tumblr/twitter) curated by a single user. They can be about any topic or anything you want. The owner of the ring dictates who can join and post. They have to approve each member, and can control membership by removing/banning people or content at any time. Only the approved members of the ring can see it's content. All posts self-prune and are permanently deleted after 7 days.