Sites where travelers can log on to sound off

Travel opinion sites capitalize on one of the things the Web does best: allowing anyone to have his or her say on a particular subject. The only problem is that the line between legitimate posts and marketing pitches can be difficult to discern. Here's a rundown of the five most popular places to click for (supposedly) unbiased observations.

Epinions.com
Its "Hotels & Travel" section contains countless postings, some of which sound suspiciously effusive. Head to the travel message boards, where all posters must submit profiles—and where suspected abuses are flagged.

IgoUgo.com
This site has 350,000 members and requires registration even for those just browsing. Recently, IgoUgo offered 13,442 posts on 2,198 topics, primarily on "Destination Chat." Under "Travel Dos and Don'ts," you'll find users venting freely about Hotwire, Quality Inn, and the Transportation Security Administration.

ProfessionalTravelGuide.com
Here are opinions on hotels, destinations, and cruises. Instead of user-generated content, all reviews are by "over 200 professional travel journalists"—although keep in mind that many travel journalists take freebies.

LonelyPlanet.com/thorntree
Lonely Planet's opinion and information site has loads of useful info on destinations, safety, and travel nuts and bolts posted by hard-core travelers who share more personal experience than they do airline or car rental complaints.

TripAdvisor.com
A sister site of Expedia, TripAdvisor claims nearly 30 million visitors a month and 10 million traveler reviews. But newcomers to the home page will first see booking tools, not opinions; searches for hotel rooms include user ratings but are not sorted by them. Dig deep to find the forums, featuring candid comments on everything from airlines (Sun Country to Qantas) to time-shares ("beware of a fake address on a vacation rental"). TripAdvisor also provides "management responses" to user reviews.