Travel expert Pauline Frommer discovered the downside during a trip to Hawaii when she visited a hotel for her Pauline Frommer's Guides that didn't match the glowing reviews on Trip Advisor. After a negative review on the site, Frommer learned, the owner had encouraged friends and past guests to submit positive ones.
Hotel booking sites such as Quikbook, Expedia and Hotels.com also have added user reviews, but these offer an additional layer of security: Only travelers who have booked the hotel through their services can post opinions.
Qualified or not, such reviews can punch up business or smash it. Forrester's research indicates that 36 percent of travelers look at traveler rankings when choosing a hotel, and of those 73 percent said those reviews shows affected their choice. Yet only 29 percent of travelers have written reviews, says Harteveldt.
Interactivity isn't just about reviews, message boards and the sort of forums long popular on Lonely Planet and Cruise Critic.
Increasingly, the Web offers tools that enable travelers to get customized information for trip planning.
Mapping -- offered by sites like Mapquest, Google Maps, Rand McNally and AAA -- has gone a step further with tools that locate gas stations closest to the airport (at Expedia) and ones like Gasbuddy (www.gasbud dy.com) and Mapquest's ''gas prices'' feature (http://gas prices.mapquest.com), which help you find cheap gas. AAA's Fuel Cost Calculator (www.fuelcostcalcula tor.com) will help figure out how much you're likely to spend on gas during a trip.
And if you're looking for fuel of another sort, Pubwalk maps pub itineraries in more than 65 U.S. cities.
As groups of friends and family have hit the road together, sites such as Triphub, where group members can discuss plans, plot an itinerary and share maps, have become more popular.
Podcasts and mobile-enabled features are also growing. Cities like Philadelphia (www.gophila.com) offer free podcast tours, while sites like Priceline have added features that allow travelers with mobile devices (such as phones and PDAs) to check real-time hotel availability, then call directly to someone who can book the room.
Whether they feature the latest technology or not, the websites most useful for travelers are those that offer accurate, timely information that's easy to access. That can range from up-to-the-hour details on lines and delays at airports (Flightstats and Orbitz); forecasts about when airfares will likely be cheapest (Farecompare and Farecast); the best and worst seats on various airplanes (Seatguru); the price of winning bids on Priceline (http://biddingfortravel.com); alerts when airfares have dropped on tickets you've already bought (Yapta); locations of pet-friendly hotels (www.dogfriendly.com); and videos of hotel rooms in Europe (TVtrip).
FIND AN EXPERT
So much information from so many sources may be overwhelming. One answer: Consult an expert.
Editorial publications like Cruise Critic, Smarter Travel, World Hum, Hotel Chatter, Professional Travel Guide, and newspapers, magazines and guidebooks offer unbiased expert opinions online.
Many feature timely blogs, such as Arthur Frommer's blog (www.frommerscom/blog); TravelMavens (www.travelmavens.net), run by the retired travel editor at The Cleveland Plain Dealer; and The Miami Herald's Travels with Jane and An Insanely Busy Person's Guide to Getting the Vacation You Need, where travelers can post comments and ask questions.
And don't forget travel agents. No, they aren't extinct.
While few travelers these days will use an agent to book a simple air ticket to New York (an agent fee might run $50), studies suggest that an increasing number of travelers are opting to shortcut the time-consuming Internet-booking process in favor of agents, especially for complex itineraries and luxury trips. And as many as 90 percent of cruises are still booked through agents.
Lang Baumgarten, a Miami real estate investor, would rather pay a service fee to his agent, Scott McGuire of Jim Eraso Travel on Key Biscayne, than spend his own time on the phone or Web.
''I think the Internet is a great tool, and if I hear about a new hotel, I'll go online and look it up.'' But when it comes to booking, he says ``I would prefer to delegate to someone who does something for a profession and really knows about it. I don't have the patience.''
Recently his agent was out of town, so Baumgarten called directly to a hotel where he has often stayed. When McGuire returned, he called the hotel back and got Baumgarten a better rate and a hotel spending credit -- earning Baumgarten more than the fee he pays the agent.