Thanks Steve. I poked around last night after getting the yard mowed, and it looks like there is a short to ground on one of the PCM relay connectors. It's not good when you get continuity from the same pin to both the positive battery cable AND the negative battery cable at the same time!
If anyone else has any insight, I'd appreciate it. Otherwise I guess it's time to start pulling plugs.
It sucks that it's on the street, it'd be easier if it were in the driveway.