Travel bargains: where to find them fast online.(travel Web sites)

Shop around at travel Web sites such as Expedia.com and Orbitz. com and you'll get good deals, and aching fingers. A fast way to find even bigger bargains is to head straight for the clearance racks of the travel industry: Hotwire.com and Priceline.com.

These sites get the flights, rooms, and cars that the airlines, hotels, and car-rental agencies are trying to unload quickly. Markdowns can top 40 percent or more. The tradeoff: Unlike other travel sites, Hotwire.com and Priceline .com won't tell you which company you're doing business with until you enter your credit- or debit-card number. For that reason, the two are called "opaque" travel sites. What you don't see is what you get. And everything is final sale; no refunds or exchanges.

We tried both sites to see which turned up the best deals. We also compared them with the leading traditional ("transparent") travel sites, Expedia .com, Orbitz, and Travelocity. We found that the opaque sites were almost always cheaper by a comfortable margin than the big, traditional travel sites. And although Priceline.com dug up lower prices than Hotwire.com in our head-to-head competition, the latter was so much easier to use that you may not mind paying a few extra bucks for the added convenience.

At Hotwire.com, you type in when and where you want to travel and the type of car you're after (for example, compact or midsized), and the site presents you with a big grab bag of travel options. To use Priceline.com, you enter bids based on your itinerary, which can be a tricky process.

THE COMPETITION

We tried the opaque sites by first identifying five itineraries for which we wanted to rent cars. We then went to Hotwire.com for rates on a car in five different cities on different dates. We took the prices at Hotwire.com and chopped 25 percent off to start bidding on identical itineraries at Priceline.com. In four out of five tries, our successful bids required modifying our requests, which added 10 to 20 minutes to our shopping time. You can't rebid for the same itinerary within seven days, so we chose to upgrade or downgrade vehicle types from, say, economy to compact, instead of changing dates or locations.

For all five queries, Priceline offered the lowest rate. Hotwire was usually the runner-up, although in two cases Orbitz matched Priceline's bargain rate. However, both times Priceline offered a car from Hertz; Orbitz vendors were second-tier operators--Ace in Los Angeles and Fox in Las Vegas. Another surprise: We found that ...