Sorry about that, fellas. Our host moved our server location early Saturday morning, and the site was loading very slowly after that (1 to 3 minutes to load a page).
Then it was a ping-pong match back and forth between us and them, with them saying it's the site's fault, it's running too many scripts and maxing out the server CPU, and us saying everything's been perfect with you guys for 7 months and we had no problems until starting a half hour after you emailed us you'd finished this server move. They did a bunch of reboots, we turned some stuff off, but nothing helped.
Sometime last night the server crashed, reset, and now all seems to be running okay. Wish I could say I knew what did it...
Chase
EDIT: correction - our lead developer, Mike, went in and fixed things up. So nothing chance here, and all credit goes to Mike. Thanks Mike!