Progress

Global score stuff is coming along very well. Got the PHP/SQL backend up pretty quickly; all that's left there is to set up caching, have a PHP-wise friend of mine double-check it for obvious vulnerabilities (I've blocked SQL injection and various nasty things that could be done to the returned plist XML, but hey, there might be something...), and make sure it'll work from the aforementioned remote server.
Client-side I'm not expecting a lot of trouble either. The structure for setting up a list of name/score views is already in place, so I've basically just got to run through the dictionary and stuff its contents into the views, and submitting the actual score request is even simpler. The one thing I'm considering right now is having it stash new-high-score information somewhere if there's no network connection available at the time; that, of course, brings in the whole encryption issue again. Blah.