The ultimate light-as-air carry-on

It's hard to beat a ballet flat when it comes to slipping through the airport security line with minimal shoelessness. A new collection from 91-year-old Spanish company Pretty Ballerinas, debuting this spring, underscores the globetrotting aesthetic. The "Around the World" line has nine styles, inspired by the flags of Argentina, Brazil, Canada, France, Germany, Italy, Japan, the U.S., and of course, Spain. (There's also a riff on the Union Jack that is part of the company's core collection.) I'm personally partial to the Brazil and Argentina styles—if only because their color palettes are less common—but the Japan also has a cool minimalist look. There's just one catch: The flats go for a steep $195–275 per pair. Check them out at prettyballerinas.us. MORE FROM BUDGET TRAVELGet through security faster (30 comments) Travel-inspiring art for sale online

Two websites that Budget Travel raves about--Yapta and Kayak--are now working together in a helpful way for travelers. Yapta helps you keep tabs on fare changes before and after you book your flight, so you can get any applicable vouchers or refunds from the airline if the price for your exact flight drops after you book. Kayak has now integrated Yapta's service into its search results. It's not happening right away, though. It'll take several weeks before you notice the Yapta "track price drops" button appear on Kayak search results. But immediately as of today, Kayak's flight search tool appears on the Yapta.com. To be eligible for a refund if the price drops, you need to book directly with the airline. Yapta spokesperson Jeff Pecor points out that,"If you book through an online travel agency, you're not going to be protected by the airline's "guaranteed airfare policy." The beauty of Kayak is that they give you the option to book the flight directly with the airline (in addition to giving you the option to book through an online travel agency, such as Orbitz." EARLIER Get money back when prices drop

Today the newly launched website TripTracker called itself to our attention for finding a way to save us from the sin of sloth. The site manages your itineraries similar to TripIt, which we've blogged about before. But it fully automates the process so you don't even have to email or upload info. You punch in your frequent flier and rewards program info once (United, AA, Starwood, Hilton, Hertz, Avis, etc.) and then every time there is an update to those accounts (such as when you make a reservation for a flight or a hotel), the data appears in the application. Glance at your trip's essential details, from hotel booking confirmation codes to the address of a key restaurant booked through OpenTable. Access the info from a PC or smartphone on the go. Your itinerary is presented in creative, helpful ways, such as a map of your flight route with live weather radar, live terminal and gate info, and your hotel's location plotted on a map. Bonus: It's free, but advertising-supported. (The ad-free version costs a buck.) TripTracker is not a product of some fly-by-night Internet startup. Instead, it's run by a Pageonce, a company that's already the top personal finance application across iPhone, BlackBerry, Android. Here at This Just In, we're just psyched someone has found a way to round up every important detail of our upcoming trip, so we have one less thing to worry about. But we haven't had a chance to take this new service during an actual trip yet. (It only launched with car rentals last Friday, and flights and hotels the week before.) If you have thoughts in the meantime, feel free to chime in. Details at TripTracker EARLIERTripIt rolls out flight monitoring perks for a fee Budget Travel's favorite apps plus more favorite apps Get money back when prices drop iPhone: Top language translation apps

Have you ever been tempted to take advantage of the vacation-rental clearance—booking a beach home or mountain condo mere weeks before check-in? Luckily, a Web site launching today will help make it easier for you to book an affordable vacation rental at the last minute: PackLate.com. The site has a simple motto: "The closer to check-in, the bigger the discount." A condo in Utah that ordinarily rents for $150 a night on a vacation rental booking site like HomeAway will be offered on PackLate for about $100 a night two weeks in advance, and then, say, $75 a night a week in advance. The site is free to use, but you have to provide your e-mail address or Facebook account access in order to sign up to see deals. This news is part of a larger trend than the mere launch of a small website. PackLate's arrival means that—at last!—the vacation rental industry is becoming more technologically savvy and its yield-management systems will be hard at work. A sale can now be launched and then ended within hours. For example, many PackLate deals are available for only a three-day, 24-hour, or even 10-minute periods. That means discounts will be lower than ever before, but only sophisticated travelers will benefit the most. Rates drop by at least 10 percent for bookings made within two or three weeks of arrival. Brokers become desperate to put some heads in their beds, rather than leaving their places empty. PackLate allows owners to offer even discounts of 45 percent off when I looked today, even for Presidents' Week rentals that are normally sold out at peak prices by now. I've got two criticisms with PackLate as it "gets out of the gate." First, it doesn't have a broad inventory of properties yet. As of today, it's focused on Colorado, Utah, and Nevada, especially Aspen, Breckenridge, Dillon, Keystone, Park City, and Telluride, though some other areas, such as South Tahoe, Calif., are also covered. Resorts in other states will be added over time, the site says. Another complaint: PackLate is primarily courting vacation rental management companies to get its listings. Our readers have found that those companies often add middleman's fees of up to 50 percent of the rent to a travelers' bill. We hope that more property owners will become hands-on landlords themselves and use sites like PackLate let them rent their rooms directly to you—with deep discounts. One bit of good news: The site plans to soon let travelers contact the vacation rental companies direclty to make an offer below the current price. One final word of caution: Don't let the time pressure force you into making a decision before you read the fine print, ask the key questions, and ask about fees. During this lingering recession, renters have enormous bargaining power. Don't settle for what's on offer at any website. You may still find that negotiating with an owner directly gives you the best rate. MORE TIPS ON VACATION RENTALS Check out our Vacation Rental Handbook. Prefer to rent through a mainstream travel agency that specializes in advance bookings? Here are the best vacation rental sites to use. EARLIER Short-term vacation rentals made easier with Zonder.com