The Web is an essential tool for travelers, but as booking engines and trip forums evolve and multiply, you have to know where to look -- and whom to trust. To help you, the following travel web sites are the top 10 in United State voted in 2008 , even in the world around.

CUSTOMIZING AN ITINERARY
Homeandabroad.com
Plan a trip to one of more than 90 destinations from start to finish. Along with all the basics (hotel, restaurant, and entertainment ideas), get tips on what to read before you go. Caveat: They tend to overpack an average day with suggestions.

BOOKING FLIGHTS (OVERALL)
Sidestep.com
Comparing top aggregators Sidestep and Kayak, we found that eight-year-old Sidestep's flight tool has a slight edge: A handy matrix at the top of the results page gives an overview of the lowest prices pulled from 600 airlines across 200 sites. And refining the search by departure time or airport is a breeze.

KNOWING WHEN TO BOOK A FLIGHT
Farecast.com
Buy now or wait for a better price? Farecast uses historic pricing data to help you make an educated decision about whether or not a fare is likely to fluctuate in the coming week. A supplementary service called FareGuard ($10) covers the difference if they tell you to wait for a price to go down and it rises instead. Caveat: Farecast covers only 78 cities, all of them in the United States.

MAPPING ROUTES ON U.S. PUBLIC TRANSPORTATION
Hopstop.com
Decide on your transport of choice, as well as how far you're willing to walk, and get point-to-point directions for five cities. Bonus features: You can see what the trip would cost by taxi and look at panoramic shots of what to expect when you emerge from underground. Plus, there's a new small-screen version for phones and PDA's. Caveat: There are no actual subway maps.

FINDING LATE-BREAKING DEALS ON LUXURY HOTELS
Lastminutetravel.com
Search hotels by ratings in your city of choice, and the site turns up an impressive mix of reduced rates on rooms at luxury properties. Our recent results: 23 percent off a room at the Biltmore, in Coral Gables, and 15 percent off at the Goring, in London. Caveat: The best deals take digging.

PREVIEWING MENUS IN THE U.S.
Menupages.com
With approximately 25,000 restaurants across eight cities, MenuPages makes it easy to plan meals by type of food, neighborhood, price or random craving (bialys in Philly?). Caveat: Menus may be a bit stale; 3,000 to 5,000 are updated per month. And, unlike at OpenTable, you can't book tables online.

TRAVEL QUESTIONS (ALL OVER THE WORLD)
Travel-Tour-World.org
This is an opening question web sites about travel or tour. All the questions are asked by traveler, so when you start to prepare your travel you maybe face the question. It have more than 30,000 articles and update 10 articles everyday. All the articles are free to read, and post a comment don’t require registration.

LEARNING ABOUT HEALTH AND SAFETY ABROAD
Tripprep.com
A comprehensive resource with recommended vaccinations, embassy listings and crime advisories for 204 countries. (Information is culled from the state departments of the U.S., Canada, Australia and the U.K.) Also included: tips on local customs and transportation. Caveat: Incomplete listings of doctors abroad. Free registration required.

RESEARCHING LOW-FARE CARRIERS IN EUROPE
Flycheapo.com
Don't get stuck on the name. This is a great resource for learning about 45 low-fare carriers in Europe. Select your two endpoints (say Rome and Oslo) and learn who can get you from one to the other on a direct flight (Denmark's Sterling Air). Caveat: FlyCheapo only shows you who flies where; for prices and schedules, you'll have to visit the airlines' own sites.

LOCATING THE BEST INTERNATIONAL AIRFARES
Farecompare.com
Decide how much you want to spend and when you want to travel, and Getaway Maps will overlay the lowest fares pulled from more than 500 airlines (most of the major U.S. carriers, as well as many international ones) for a select range of cities.