This week, Kayak.com announced three new tools that will make finding and sharing travel deals easier than ever. We’re very aware that times are tough right now. For many travelers, the right airfare is the key factor in embarking upon a new trip this winter - or staying home. And while we admit that it has become more difficult to suss out the deals, there are definitely deals out there to be had - the hard part is finding them. Each of Kayak.com’s new tools was created to help travelers do just that.

Here’s the lowdown:

1. Kayak.com Collaboration Engine: In an industry first, Kayak.com now allows travelers to share all results for air, hotel, rental car and cruise searches. So what does that mean, exactly? It means that you can collaborate with friends and family members by viewing the same search results simultaneously. You can also sort and filter those results in real-time, share the results quickly via email and save favorite itineraries or searches for all of your travel companions to see.

Here’s what Kayak.com CTO and Co-Founder Paul English had to say about it:

“If you find a great deal for a romantic winter getaway, but want to confirm details with your girlfriend before booking, the Kayak Collaboration Engine allows you to both look at and modify possible flight or hotel options in real time. This process is much faster and efficient than describing what each person sees on their screen over the phone. Or worse, waiting until you’re in front of the same computer to make a decision only to find the price has significantly increased.”

2. Kayak.com Buzz Calendar (pictured): The Buzz Calendar combines two of Kayak.com’s most popular tools, Kayak Buzz and Flexible Search. Once a user inputs a destination airport and travel dates on the home page, the Buzz Calendar will instantly appear and offer a snapshot of travel pricing for the next month. For each day of the month, the Buzz Calendar displays the best price for travel found by other Kayak.com users during the past 48 hours. The most affordable dates of departure are highlighted. So even before travelers begin their search, they’ll know where to find the best deals.

Kayak.com EVP of Corporate Development Keith Melnick explains the new feature like this:

“Flexible Search is one of our most popular tools, but users requested the ability to compare prices over a longer period of time. Price-conscious travelers can now view a snapshot of fares prior to choosing dates and kicking off a search. The Buzz Calendar is also the fastest way on the Web for lookers, not ready to be bookers, to quickly check departure prices, without waiting for a search.”

3. Kayak Insight: Bored? Travel voyeur? Then Kayak.com has a tool for you. Travelers looking to kill time or find unique trip ideas can watch LIVE searches displayed on a unique Google Map. Kayak Insight displays real-time searches that other Kayak.com users are requesting, along with the cheapest fare available. As a search is performed, a text box appears with itinerary details and price. This new Google mash-up provides a fascinating “fly-on-the-wall” look at the best deals Kayakers are finding from the user’s home airport.

Interested in going to Europe? Move the map to Europe to see best prices appear. By clicking on “Search Now” travelers can see all results for that itinerary and choose their own adventure. Kinda cool, right? We certainly think so!

If it’s going to cost more to fly, then you might as well snag an itinerary that not only gets you to your destination, but does it on your terms. Hence the Kayak.com Flight Quality Filter, a new tool we’ve added that allows travelers to filter search results to weed out common travel mood killers like long layovers, red-eye flights and tiny turbo prop planes.

You’ll find the Flight Quality Filter on the left side of the search results page. At the same time, we’re also flagging certain flights within search results with a “Flight Quality Warning.” Be on the lookout for symbols that represent several factors that may sway a flier’s choice, including a short connection time (under 45 minutes), long layover (over four hours), terrible on-time record (75 percent or less), departures and returns from different airports, red-eye flight, few seats remaining (only one or two seats left) and turbo prop planes.  By hovering the mouse over the symbol, a text box appears explaining each warning.

The new flight quality tool isn’t the only cool new feature we’ve added recently. The next time you rent a car, try the Fuel Cost Calculator and the Miles Per Gallon Filter in the Kayak.com Car Rental area, as well as our frequently updated Airline Fees page.

Meet two of the latest travel tools from Kayak.com: the Fuel Cost Calculator and the Miles Per Gallon Filter, both of which now appear alongside car rental search results to help travelers determine the total cost of their car rental before they book a reservation.

As you can see in this screen shot, I pushed the MPG Filter (on the left, half way down the screen shot) all the way to the right in my hunt for cars with the highest gas mileage - and my options dwindled to far fewer cars than my original search produced.

Above, Kayak.com’s Fuel Cost Calculator - an industry first - estimates the total cost of gas for a trip and instantly adds this figure to the daily rate of each car option. The Fuel Cost Calculator takes into consideration four factors:

- miles per gallon for each vehicle

- average price of gas

- number of estimated miles traveled during trip

- type of driving (highway, city or both)

Sure, other fuel calculators exist, but ours is the only one that instantly updates the total price of a car rental per day so travelers can easily compare the final price across rental car agencies and car class.

You may have heard tell of Kayak’s new approach to airline fees in glowing little bits of press like the Boston Globe’s Flustering Fares piece from last week. We’re excited about being able to offer travelers the option to include airline fees in the total ticket price when they search for airfare on Kayak.com. Lookout for that new offering in the coming weeks.

In the meantime, we’ve added a rockin’ new feature that you can use right now:

Kayak Airline Fee Chart

We’ve been checking fees, adding airlines and rechecking fees for the last several weeks to bring you this spiffy chart delving into the intricacies of airline fees associated with economy class travel. Be forewarned that we are concentrating on North America/U.S. and Canada routes right now. In most cases, the fees listed apply only to routes in those regions. Also, we’re updating the entire chart once a week, sooner when major fee changes occur, so make sure to check with the airline directly if the presence or absence of a certain fee is crucial to your trip.

You’ll see a link to this page when you search flights, and we’ll be mentioning it frequently on the Kayak blog.

Have questions, comments or corrections for us? Feel free to get in touch with your feedback and suggestions for improving this new feature on Kayak.com!

One day, you fly free of charge with asinine amounts of luggage. The next, you’re paying up to $50 per trip to check that second bag. If you’d known the airline’s policy, you might have rethought your packing strategy, shipped excess luggage to your destination or simply brought extra cash to pay the sky cap.

I put together a quick-reference chart that lists U.S. carriers, the charges for 1-3 checked bags and links to each carrier’s detailed baggage policy.

Checked Bag Airline Surcharge Chart

** Note that airlines are constantly changing their policies and fees - so always check directly with an airline for the most accurate and up-to-date information. Also, this chart covers basic checked bag charges and does not delve into the realm of overweight bags - we’ll handle that in an upcoming post.

Do you have a travel surcharge conundrum that you’d like us to investigate? Leave a comment, and we’ll get on it.

We’ve added a new feature to flight results today. You might not notice it at first, but it can be very handy. Suppose you have some flight results like these:

Those are a lot of options on American. Suppose you like one particular outbound leg, and you don’t want to look at any other options that doesn’t include that leg. Let’s say you want to arrive in SFO at around 5:30pm. Just place your mouse cursor over the outbound leg you want, and a little green bubble will appear:

Now, click, and the outbound leg will “lock” up in the top of the results, and you’ll only see results that match.

You can do the same thing with return legs. Let us know what you think.

We’ve had Kayak Mobile for a while, a really bare bones hotel and flight search application. It’s basically designed with the idea that you are either at an airport and need a one-way flight, or you are in a city somewhere away from home and you need to find a hotel for tonight.

But more modern phones, like the iPhone, can do more with the web, so we created a UI that is somewhere in between for them. The basic idea is that you can do normal round-trip flight searches, and normal hotel searches. The biggest differences are:

• many UI elements have been dropped to fit the smaller screen
• while booking links are still present, the phone numbers for the airlines are more prominent. On an iPhone, for example, you can touch the phone number, start dialing, put it on speaker, then return to the web browser to read the flight details to the airline rep.

This is just our first cut at this. As always, we welcome your thoughtful feedback for improvements.

It’s Thursday. At Kayak, that means we’ve released a new version of kayak.com. What’s new this week:

A lot of users have asked for this, and we now have advanced technology (the engineers called it “multiplication” and “division”) to show you your flights in whatever currency you want. Got a bank account full of Phillippine Pesos? No problem. Canadian Dollars? Got it. Just sign in and change your profile preferences, and we’ll calculate the price for you. You’ll still have to pay the airline in whatever currency they sell in, but at least you’ll know what you’re spending.

We’ve added a new web site, kayak.es. If you’re Spanish, you can now use Kayak with your language, and search travel sites that will serve you better. Bienvenido!

We also have improved fare alerts significantly. You can now specify exact dates, any trip length you want, any cities you want, and we’ll alert you to the fares.

Here is how you set up an alert:

And here is what you’ll see in your email inbox:

To use this feature, go to your email preferences.

We’ve also made a number of internal changes which should improve the speed and reliability of the site, as we do every week.

If you have any comments or complaints about these new features, or anything else to tell us, please use our feedback system. A real human will read your message and answer you.

Kayak.com pulled the plug on Kayak Forums today at 7:59 a.m. The product died of malnutrition as a result of neglect.

The death was confirmed by Kayak.com CEO and Co-Founder Steve Hafner who said, “Although we will miss Forum’s sage advice, willingness to listen and ease-of-use, he was wasting away, starved for attention. Kayak.com is committed to excellence and Forums were unable to compete with over-achieving siblings Kayak Buzz and Flexible Search. Although Forums may never be replaced in our hearts, he will be replaced on the website with new industry-leading innovations.”

Kayak Forums encouraged users to share travel tips, but too few heeded the call. He listened while consumers requested advice, although few answered their cry for help. He laughed alongside travelers as they reminisced about recent trips, but only Kayak engineers cared. He even sent members personal notes when their favorite topics were being discussed but where were the thank you notes? He knew the end was near.

To honor the memory of a fallen comrade, Kayak.com will continue to enhance the Buzz product and is working on designs for Kayak 2.0—an unprecedented site redesign—scheduled to be released in May.

Kayak Forums are survived by fraternal twin, Kayak Blog and other high-flying siblings: Kayak Buzz, Best Fare History, Best Fare Trend Graph, Flexible Search, Fare Alerts and the Trip Ideas newsletter.

In lieu of flowers, Kayak.com asks that you “Tell a Friend” http://www.kayak.com/h/friends about Kayak.com.

I dreamt to-night that I did feast with Caesar,
And things unlucky charge my fantasy:
I have no will to wander forth of doors,
Yet something leads me forth.

Julius Caesar, Act III, Scene III

What better day than the Ides of March could there possibly be for a software upgrade? Seriously.

Today, we bring you:

1. A better buzz. Weekend trips! Non-stop!
2. Tell-a-friend about Kayak!
3. A bunch of boring technology stuff that will help us handle the growing traffic.
4. Kayak search API supports UK searches (via www.kayak.co.uk).
5. Many bug fixes, including the notorious “adding Coeur d’Alene, Idaho to profile causes google map not to show.” I know you were waiting in agony for that one!