Bookmark the article from the repository to Connotea
See tags applied to an article (only if it has already been bookmarked)
See links to other articles that share those tags (filtered to articles in your repository)
…del.icio.us also recommends items for a given tag
See Related items for a bookmark
See some other methods on an earlier blog post
…I really like the idea of social bookmark services being an extensible module to an external database.
There are services like FreeTag but I’m talking more about using an existing service as part of a driver to your service.
You could also leverage on the annotations, ie. comments field in the bookmark services to describe the library item.
So for each library record you could see what other items have been applied with the same tags, also see related items, and recommended items.