Thanks wazzat & nealtw!
When I lived in Indonesia for a year there was one in the house where I stayed. That was 20 years ago and I didn't pay much attention to what it was but I remember it well. I never ran out of hot water. Ran out of water once in a while when they didn't fill the water tank though. It never failed but was kind of ugly inside the western style bathroom.
I've talked to a couple plumbers and they aren't very pro-tankless. Have either of you used one? I'd sure like to hear some firsthand experiences.