Thanks, Pete, I didn't know about that!
Scott, I'm working with very basic hosting packages that don't allow remote connections to the DB. I don't know from the specs on RedGate (which I can't afford anyway) whether they provide a workaround for that, and although there are also API's out there (such as the one from Apex), I didn't see the point in investing in a solution that was still going to require more programming on my part. :)
My solution is to drop an ASPX page on the site that acts as a kind of "schema service", returning the collected metadata as XML. I set up a little AJAX app that compares any number of catalog instances to a master and shows the diffs. It's not perfect, but a major step forward for me.
Thanks again!