Who hasn't wanted to live in a tree house? I came close to buying one twenty years ago - it was the most impractical structure you could imagine: little privacy, one big room, hard to climb up to, dangerous balconies for kids - it would have been like living in a well equipped tent. Cooler heads prevailed and I was convinced by others that it would be a mistake.
Recently I read about these great bamboo houses in Bali and found out that you can rent them. We're going there at Christmas and we might stay in one of the "Green Houses" if we can work out the dates. The concept of building out of bamboo makes so much sense in Bali. If you want to read about Elora Hardy, the designer, and the whole project, take a look here. All of the photos below are from airbnb who are the rental agents or from the Green Village project web page.