…As little as possible. But how successful is the e-travel crowd at finding the lowest fare? Here's how four Texas-based Web sites—travelocity.com, travelweb.com, aa.com, and southwest.com—and a real world, not-com travel agency, Christopher Travels, in the Austin suburb of Lago Vista, stacked up against each other. The goal: Find the cheapest round-trip fare between two cities based on specific travel dates regardless of travel times or itinerary.

1. A long weekend trip (Thursday to Sunday) to Los Angeles from Austin. Twenty-one-day advance purchase. Best: $198 (travelocity.com) Worst: $259 (aa.com)

2. Business trip to the New York City area from Austin, leaving on Monday and returning on Wednesday. Six-day advance purchase. Best: $528 (Christopher Travels, which found a cheap fare that required a change of airlines in Dallas) Worst: $1,488+ (everybody else)

3. Holiday weekend trip for four to Portland, Oregon, from Austin. Sixty-day advance purchase. Best: $776 total (travelweb.com and Christopher Travels) Worst: $900 total (southwest.com)