Connexions employs a powerful post-publication vetting system called Lenses, where users can highlight quality content. Lenses enable both organizations and individuals to give their stamps of approval to content in the repository, allowing for user-driven quality control of modules and collections. Through these lenses, users can provide their own tags and comments for items in the repository. Lenses can also be used as "bookmarks" within the repository to keep track of related or otherwise interesting content.
A list of all publicly-viewable lenses can be found at http://cnx.org/lenses.
For more information on using lenses to find content, look at our help page on lenses.