I spent a little time today playing with Ma.gnolia, a new social bookmarking site currently in beta. Ma.gnolia was built in San Francisco by Larry Halff using Ruby on Rails and some design help from Jeffrey Zeldman and Happy Cog Studios.
Ma.gnolia includes standard bookmarking features such as a title, a description, and some tags but the application does a good job of connecting those bookmarks to other groups of users with similar interest. You can browse groups to find like-minded users and subscribe to a group pool of interesting links.
Groups allow members to stay involved even if they never add their own bookmarks. Ma.gnolia allows you to mark personal bookmarks as public or private, share with a friend, or share with a group. Groups can be moderated or open to the public. Every member can rate a bookmark on a scale of 1 to 5 to easily sort through favorites of favorites.
The rich data of groups, ratings, personal connections allows Ma.gnolia to build search relevancy tools to help people find what they may be most interested in among thousands of results. Find what you want and look good doing it.