You can send private messages to other members of lonelyplanet.com.
View your messages by selecting ‘Messages’ from the drop-down menu under your profile picture, or by clicking on ‘Messages’ at the top of the page when you're on the Thorn Tree forum. To write a message, click on ‘New message’ on the left of the page.
Alternatively, you can message a member by clicking on their username or profile picture while on the Thorn Tree forum. This will bring up a window with a ‘Send private message’ button.
Some members choose not to receive messages from strangers. They have to add you as a contact before you can send them a message.
For information on this setting, see: How do I stop people from contacting me by private message?