There's an interesting discussion about tagging and OPACs over on the WEB4LIB mailing list. Start here and work your way through the thread (so far the subject line hasn't changed so it should be relatively easy). Some interesting comments and pointers to the PennTags project at Penn State the University of Pennsylvania, which I didn't realize incorporated tagging into the catalog. Rock on, Michael Winkler and Penn State UPenn!

In addition, make sure you stay current on what Davey P. is doing with his OPAC, in particular the pewbot which provides Amazon-like suggestions (read more about it here and here).

Earlier this year, John Blyberg did a great job surveying some of the really great experimenting we're seeing with taking OPACs to the next level. Could 2006 be the year the OPAC finally begins to truly evolve? Let's hope so.