So today I had electricians out to do some work.
This involved cutting power to, among other places, the shelf where my four PiDPs sit.
But then when the power came back on....all I had to do was toggle "start" and the blinkylights came right back on.
(yes, yes, I'm not a COMPLETE idiot, I realize that the memory state is saved on disk, but the point is, the pi rebooted, and the file containing the memory was right where I left it and journaling filesystems are just fine these days, and the point remains, I just had to push the switch)
Adam