Is there a way to get all information for a url (from everyone)?

I'm thinking about creating a bookmarking helper, one that would provide sample tags, an aggregated rating, a sample description and a sample title. I haven't been able to find anything for computer-reading. The closest I've found is Roots, but that's for humans and I'd like to have the helper aggregate multiple sites (del.icio.us also). The API does allow searching for a URL, but only through a user's bookmarks, not everyone's.