Lonely Planet
Lonely Planet's online community, the Thorn Tree, was created in 1996. It is named for a Naivasha thorn tree (Acacia xanthophloea) that has been used as a message board for the city of Nairobi, Kenya since 1902. The tree still exists in the Stanley Hotel, Nairobi. It is used by over 600,000 travelers to share their experiences and look for advice. Thorn Tree has many different forum categories including different countries, places to visit depending on one's interests, travel buddies, and Lonely Planet support.