Userscripts.org

There are dozens of scripts that tell you whether your library owns a book (and whether its checked in) while you're looking it up on Amazon (such as #6641), but they're all for specific libraries. I'd like one for the University of Rochester library (catalog.lib.rochester.edu), but I think the public good would be better served if someone could figure out a way for users to customize it for their preferred library. It might be easier to write a script for each type of catalog software (Voyager, Innovative, Talis, etc.). Or would this be more suitable for a Firefox extension?