Today, Farecast, a free online service that helps travelers decide whether they should buy a ticket now or wait and hope that the price drops, has begun to forecast ticket prices for 200 international routes for flights departing within the next six months. Until now, the site only predicted fare trends on most major domestic routes. The website makes its predictions primarily by searching for patterns in ticket prices recorded in computer databases for select routes to Europe, Mexico, Canada, and the Caribbean.

Farecast is the only fare prediction website that tells you in a clearcut way whether a ticket is a fair value, with big bold-faced words like "buy." The site also leads the field in making it clear how confident it is in its predictions about whether fares for your itinerary will rise or fall during the next week. Unfortunately, by limiting its predictions to what prices will do in the next week, Farecast doesn't resolve the question of whether to book now or wait another month (or any longer period of time). It's best for travelers who are ready to pounce on a deal.

Farecast, you'll recall, is the winner of Budget Travel's 2007 Extra Mile Awards, and we've blogged before about its airfare prediction tool for domestic flights.

Some of Farecast's other new tools include a tab for "Prediction & History details." If you want to know just how expensive it will be to fly to, say, London in July, Farecast will tell you. If you want to know how those London fares compare with the fares for flying to other European capitals, you can click a few buttons and the Farecast will display an easy-to-understand graph comparing fare trends between the cities. You can quickly see if you'd get more bang for your buck by flying to, say, Rome, instead of London in July. Predictions are limited right now to trips lasting between two and eight days in length.

Farecast is not offering insurance on its price predictions for international trips—at least not yet. For domestic trips, in contrast, the site sells a Fare Guard option for $10 that guarantees you can buy lowest fare you see today, even if that fare disappears later in the week. (As Laura MacNeil explained this option in a Budget Travel story last year, "If the company is wrong and the price goes up—and you book a ticket within that week—you'll receive a check for the difference between the original quote and what you ended up paying. If the price goes down, your $10 will, you hope, be made up for in the savings.")

EARLIER Starting in May for domestic flights, United will only allow you to check one bag free, charging you $25 for your second piece of checked luggage, $100 for your third, and $100 for your fourth.