Will this I2C isolation circuit work?
I was thinking about this same thing yesterday and came up with this thread when I searched. I know there isn't much need to re-invent wheels, but it is a fun design problem, and who knows, one day we might need something in a hurry and have to make something from the spare parts drawer. So - what about this? I think it does the job. Only one open-collector line show,  the two are the same. One dual-opto per line.