Apologies if this has been discussed in depth but a couple searches came up with nil.
I'm currently using Adobe Bridge to manage my image ref. library but I don't love it. It crashes more often than I'd like and it's no speed demon. I'm wondering if there's another piece of software or a workflow that a lot of people find successful.
If you're on a Mac, I highly recommend Apple's iPhoto (comes with new Macs). The newest version has surprisingly useful things for organizing photos such as facial recognition (could group model shots) and has many other more basic organizational tools as well.
I hadn't wanted to use iPhoto because I didn't want all my ref. pics mixed in with my personal and family photos and all that but your suggestion got me wondering if you could have multiple iPhoto libraries...you can!
Maybe that's not news to everyone but it was to me. I'm in the process of dumping all my ref. into a brand-new library right now and will slowly, slowly start tagging it all so it's searchable and easy to navigate.