Update: the article and the photo to which the posting used to link to has disappeared (for ever?).
From today's (December 6, 2007) Bangkok Post an in-depth article on the national park surrounding the hot springs of Fang (which I visited a month before). An excerpt:
'For those of us who prefer to enjoy nature after sunrise, there are beautiful wooden bungalows where you can stay cosily warm and enjoy resort-like facilities. Four of us shared a two-room bungalow which had a hot bath and a big balcony where we sat talking until late into the night. We also took advantage of the spa and sauna, which were only a short walk from the bungalows.
The park uses a nearby hot spring to generate electricity, said Sutheerachai Jaikhamnoy, the park ranger. "The temperature of the hot spring is pretty high, so we make use of the heat by having a small geothermal energy plant," he said. The power generated is not solely reserved for internal use, but is sold on to the Provincial Electricity Authority. There are many hot springs found in a 10-rai area near the park's headquarters, the most spectacular being a geyser that shoots water and steam 40 metres into the air.
The park has set up a hot spring walking trail, allowing visitors to fully enjoy the many stream and ponds. The trail also leads to 12 private spa rooms, each of which has a hot-spring bathtub big enough for seven people. And, of course, there is plenty of opportunity to indulge in that favourite Thai hot spring activity - boiling eggs'.