Rough Guides are the publish some of the best travel books in the world. They also maintain a discussion forum called Travel Talk. It doesn’t get as much traffic as Lonely Planet’s The Thorn Tree. Unfortunately, Travel Talk is prone to spam from tour companies. There was even a post in the South America forum from a tour operating touting Ethiopia! Also, it seems like some of the postings on Travel Talk were may have been biased comments from people associated with a particular travel agent, hotel, etc. The comments on the Thorn Tree seem to be mostly from genuine travelers.