http://tropical-treehouse.com/page1.html
A bamboo hooch treehouse created and built by Jo Scheer. Props Jananda.
http://www.pachamama.com/
A place in Costa Rica that I came across through Ruben from Belgium in Mazunte, Oaxaca, Mexico.
http://www.tucanhotel.com/
Tucan hotel / hostel recommended by Chrissy in Guatemala.
http://www.costaricabackpackers.com/
Hostel with free wifi in San Jose, Costa Rica. From $12 a night in the dorm. Has a garden, pool, etc.