Well, thanks to the worldwide DCI Judge community and especially Jason Lemahieu, there's an answer! Twenty-four hours a day, seven days a week, there's someone on the #mtgrules IRC channel waiting for your question. Rules questions in the channel are answered by volunteers from around the world. Certified judges (and other rules experts) just idle until a question comes. The fact that the volunteers are so spread across the globe is what makes it easy to be 24/7.
Now, let's say you don't already know how to set up an IRC client. Well, that's no problem. Because DCI Judges are problem-solvers! There's a convenient web client at http://dcifamily.org/askthejudge/ where you can ask rules questions. Enjoy!
(Oh, and note that this is only for rules questions, not random chatting.)