Hooray! Got the site back up! Apparently Internet connectivity (rather, lack thereof) was a common issue in Georgia the past day or so, and during all this downtime my provider decided to switch some modem settings without telling me. My router stopped talking to my modem, so even though I tested the modem connection directly once, I should not have assumed that it meant anything.
You know, there used to be a time when people would send you a mailer with your monthly bill when they planned on changing the terms of service on you. That way, you were prepared.