Lido 7 recognized it as a 4 GB drive, and it's formatting now. It's been going for about 15 minutes... a progress bar sure would be nice. But the drive is still making noises, so I assume it's working ok.

Don't hard drives have their driver software stored on the disk itself? Maybe the driver code was PPC-only, which is why I couldn't mount the drive on a 68030-based IIsi? I've never tried moving a drive between a PPC and a 68K Mac before.