Social Bookmarking Meets Social Networking: Blue Dot - Oct06 Robin Good:
While with traditional social bookmarking services like del.icio.us the emphasis is satisfying a personal need while allowing the whole world to benefit from it, the relationships that ensue are often very impersonal and limited to extending one's own ability to find interesting content without ever socializing with those serving it you. which one might prefer over . . .
..more intimate hmm social networking experience. Rather than sharing your opinions with the world, Blue Dot offers you a way of entering into a dialogue with the people you already know.

Sites you bookmark with Blue Dot are then sent to your personal list of ‘dotted’ sites on a private page. What’s nice is that whatever your friends or colleagues will bookmark themselves will also appear within your personal Blue Dot page making the cooperative collection and sharing of valuable web resources a breeze.

...the ability to combine closed-group social networking with effective social bookmarking does indeed open up new and more effective opportunities for more effective collaborative work.
..no reason why this service should not sit comfortably alongside de.licio.us in your browser, as it aims to fulfill a different need. while de.licio.us focuses on the self-interested open tagging and archival of relevant web resources, Blue Dot pushes the ability for online communities to efficiently share the discoveries of its members in a cohesive fashion.

• del.icio.us - Perhaps the best known social book marking site, del.icio.us has served as a model for those that followed. del.icio.us has in its favor the sheer number of users contributing to its vast range of tagged websites. Blue Dot differs in adding small social groups to the de.licio.us equation
• Simpy offers the opportunity to add bookmarks directly to your blog using RSS and ATOM, and also features the ability to sync with the more popular de.licio.us service.
• Stumble Upon takes a refreshingly different approach, by taking users to seemingly random pages that have actually been selected via the cross referencing of your own preferences and the recommendations of other users. The element of surprise is perhaps its greatest asset. yeah. and also I like being able to click on the rvw button and see comments about whatever webpage I'm on.
  
• Trailfire adds the innovation of linking a series of annotated pages together into a trail, which friends and family can then move through, following your annotations from one linked page to the next and creating a flowing narrative between them. Trailfire was recently reviewed in Masternewmedia. I hadn't heard of this. from skim, dsn't seem more useful to me than just succession of pagemarks.
  
• For a more extensive list of other contenders in the social bookmarking space, Read/Write Web’s excellent Social Bookmarking Faceoff is a great place to start.