If you have some time to invest when planning your vacation, and you have access to the Internet, you can save an absolute fortune by planning and booking your travel arrangements online. Airfares, hotels, and rental cars can all be reserved and paid for using the Web and a major credit card.

When using the Internet to plan and book your own travel, you have three primary options:

• Visit the Web site of the specific airline, hotel chain, and/or rental car company. For example, if you're booking your airfare on US Airways, you'd visit www.usairways.com. Often, each individual airline offers discounted online-only fares and specials that cannot be obtained anywhere else. The drawback to using an airline's Web site is that to shop around for the best fares, you'll need to visit the Web sites of multiple airlines.

• Utilize the services of an online travel-related Web site, such as Travelocity (www.travelocity.com), Hotwire.com (www.hotwire.com), Expedia (www.expedia.com), Orbitz (www.orbitz.com), or Yahoo! Travel (http://travel.yahoo.com). These services allow you to quickly search all of the major airlines for the best flights and fares. You'll also find great deals on hotels, rental cars, and travel packages. When using one of these services, the more time you spend exploring them, the better your chances of saving a lot of money will be. Once you know when you want to travel, try searching for better fares by altering your travel dates slightly. Sometimes, leaving a day earlier or later, for example, can save you money. You can also try looking up various airport combinations. For example, if you're flying from New York's LaGuardia Airport to Orlando International Airport, you can also look up departing flights from Newark Airport and New York's Kennedy Airport. Checking each variable takes only seconds using one of these online travel services.

• If you have a somewhat flexible travel schedule, you can save between 30 and 70 percent on airfares, hotels, and rental cars using a service such as Priceline.com (www.priceline.com), Last Minute Travel (www.lastminutetravel.com), or TravelHub (www.travelhub.com/airfares). Many of these online services now offer even greater package deal savings if you book your airfare along with your hotel and/or rental car.