You managed to get the right answer with the wrong math. It was 20 lbs for 2 meters. They talk about a run-time of 30 minutes, which would be about 100mW.

They say in the video that it gives "gentle glow" for 30 minutes. For brighter modes you will use faster modes, which is still cool.

I don't think they ever said how bright the light is, so it might "work" in a very technical sense.

Kerosene lamps are not bright. It is hard (but possible) to read by one. I'd love to see a calculation that takes this into account. How long would this device set at the brightness of a typical kerosene lamp last?

Depends on the kerosene lamp. I have a flat-wick lamp that I picked up for about $10 (at the supermarket as an "emergency lamp") with about the same size and with a similar chimney as this one: http://en.wikipedia.org/wiki/File:SwissKeroseneLamp.jpg

It is very easy to read by, easily lights up the whole room in a decent warm glow.

The lamps that people use in these countries are very different from that, being made with makeshift wicks and founts and generally no chimneys. Even so, the light they put off is much better than your average candle.

See the numbers elsewhere in the thread. LED light output comparable to a kerosene lamp for 30 min. is reasonable with the numbers they've given.

It's comparable in brightness to a kerosene lamp, which is what it's supposed to replace.