Who needs Fodor's, Frommer's, etc.? When planning a trip, I always chat with friends first to get insight on where to stay, what to do and so forth. I want details, and honest feedback.

Social networking sites are begining to key in to the demand for this type of experiental knowledge. In addition, Yahoo's trip planner has more than 20 000 member trip plans on an interactive world map, competitors include: Trip Advisor's INside, VirtualTourist's Trip PLanner, Gusto, RealTravel, TrekkerTime, Squidoo. To keep marketers at bay, people can comment on the iterneraries.

As these services expand, I wonder if the lawyers will come knocking as people provide emotionally charged reviews of hotels they disliked? Aggregated to 100's or 1000's of negative reviews, it could be really bad for business.