How Internet sites stack up against travel agents.

Even if you haven't tried them, you've probably heard about the profusion of services for booking travel arrangements online. New services let you investigate and book plane tickets, hotel rooms and rental cars through the Internet.

Do they make sense for business travel?

The answer depends on you. If your time is at a premium, use a traditional travel agent and stop reading right now. But if you are a do-it-yourselfer and have a little time to do the research yourself - or if you want to find out about ways in which online services are beginning to compete with traditional travel agencies - read on.

Travel sites, like Expedia.com and Travelocity.com, generally provide the same information that travel agents can access. However, the trick is sorting through it. You're generally limited to punching in the dates and approximate times for flights to and from your destinations.

What would be really helpful (at least for bargain hunters) is the ability to see a range of flights and times that roughly match what you're looking for. Sometimes the difference of a day or a week can make a difference of hundreds of dollars in the price of a ticket, but unfortunately the online sites generally leave you to figure this out by trial and error.

One noteworthy difference is Priceline.com, which lets you name a price for what you want. The system then tries to find out if a major airline will sell you a ticket for that price.

The catch is that you're only likely to get really good deals at the last minute. Before you can start the search, you also have to "guarantee" it with your credit card.

If Priceline finds a ticket (or hotel room) at your price and with the criteria you've specified, you've bought it.

Most travel sites also require you to register before you can use them, which is a free but tedious process. The payoff for you is that with more personalized information, these services can send you automatic notification about special offers, although they tend to be most useful for last-minute weekend getaways, not business trips.

Registering is made easier by the auto-fill option in new versions of Microsoft Internet Explorer. Bonus frequent-flyer mileage just for signing up with some services can also sweeten the deal, especially if your business trips have brought you close to a free ticket that you can use for a personal vacation.

A lot of the time when you go to a travel agent, all they give you is the same information you could have found out about online (or for that matter by calling the 800 number for your preferred airline).

But a good agent knows where to look for better deals (including, sometimes, options that don't show up through the online services) and can call you back to suggest the best possible arrangement. I recently did research online for a ticket, but a travel agent then beat the price by $250 after checking into other options over the next week.

"The greatest thing about the Internet is all the information that's out there. The worst thing about the Internet is all the information that's out there," quips James Ashurst, spokesman for the American Society of Travel Agents. "Somebody's got to make sense of it all."

Ashurst said travel agencies generally haven't seen business decline, even though it's easier now than ever for travelers to arrange tickets themselves. He suggests that most travelers recognize that they don't always know all the right questions to ask, sort of like the way most people don't know all the ins and outs of the tax code.

"There are a lot of online lookers," Ashurst said of travelers who research their tickets online. "But online lookers have not become online hookers as fast as people would have you believe."

People still come to travel agents because, by doing it yourself, you don't get "the peace of mind of knowing that you got all the information that is available."

Also noteworthy for behind-the-wheel business travel are trip-planning CDs (especially the excellent Microsoft TripPlanner) which let you plan itineraries for road trips with detailed driving instructions and customized maps.

Depending on the product you use (another strong offering is Rand McNally's TripMaker Deluxe), you can also go online to book flight or hotel reservations, check for road construction, or even locate necessities and conveniences along the way like ATM machines.

Christopher Ott is a freelance technology writer and can be reached at [e-mail]. Individual questions cannot be answered, but suggestions for future columns will be considered.