If you don't know about the Social OPAC application suite--an open source social discovery platform for bibliographic data, you're really missing out. SOPAC (Social Online Public Access Catalog) is a Drupal module that provides true integration of your library catalog system with the power of the Drupal content management system while allowing users to tag, rate, and review your holdings. User input is then incorporated into the discovery index so that SOPAC becomes a truly community-driven catalog system.
I Talked With John about SOPAC, and how it's used. (note: the recording got a bit messy, our voices end up overlapping towards the end of the recording).
Some of the other features of SOPAC include:
* Faceted browsing
* Ajax-empowered interface with native jQuery support
* 100% customizable interface via the Drupal template system
* Ability to remove search limiters
* Saved searches
* Integrated renewals, holds placement, and fine payment
* Ability to customize the user experience via the administrative control panel
* Ability to create custom functionality via a Drupal sub-module