Delta scans tags on baggage periodically through its journey, and having this information makes it easier for the airline to find a misplaced bag. But that same technology can be used to provide peace of mind, as Delta travelers can now use Delta's mobile application to track their bag's journey. In addition, flyers can use the application to determine the baggage carousel where their bags can be picked up.

You can find out more about Delta's new mobile baggage tracking here.

Meanwhile, the airline posted a video on YouTube to show how it all works, and its pretty easy:

And, if you're interested on how your bag gets from Point A to Point B, Delta last week uploaded a fascinating behind-the-scenes video filmed from a checked bag:

The Dallas-based airline has set up a website, AA.com/Restructuring, which has some handy FAQs.  Here's one important bit of info for people who already have reservations:

Will the flights I have already booked change as a result of the Chapter 11?

We will continue to operate our regular schedule of flights, and there are no immediate changes to our service or schedules as a result of the Chapter 11 filing. Tickets will be honored, reservations are fully intact and our policies regarding exchanges and refunds remain the same.

And as for the miles:

Are my AAdvantage miles going away?

No. We will maintain our AAdvantage program and ensure that all miles and elite status earned by members remain secure and intact. As usual, your AAdvantage miles do not expire as long as you have qualifying account activity at least once every 18 months. Qualifying account activity is defined as any AAdvantage mileage accrual or AAdvantage award redemption.

So, in short -- yes, American does have its fair bit about financial troubles, but there's no reason to worry about your upcoming reservation for Christmas travel, for example.

• The Q400s flying for Continental/United seat are similar in size to the large regional jets in the United Express fleet, they don't have first class or Economy Plus. That will be changing.
• The 14 domestic 767-300s flying for United will be upgraded, and receive flat-beds.
• United is well-known for its Channel 9 offering, which allows passengers to listen to air traffic control from their seat (it's the captain's choice to turn it on or off). This feature will begin making its way to the Continental fleet. Many fellow airline geeks (myself included) were concerned about this. Seriously.
• The airlines p.s. service from JFK to LAX and SFO is getting an overhaul. First class is going away, but expect refurbished cabins featuring on-demand entertainment.
• United's A319 and A320 aircraft will receive an interior update, and, more important, will be equipped with larger overhead bins.

Overall, these are some nice changes, and I look forward to seeing United implementing them.

The concept, of course, sounds very exciting, but unfortunately you'll have to pay up. TV shows start at $0.99, while moves will set you back at least $3.99.

So far, the new service is only available on American's 767-200s, which primarily fly from JFK to Los Angeles and San Francisco. The carrier has said, however, that the service will be rolled out to all of its mainline aircraft equipped with Gogo's inflihgt Wi-Fi service.

Here's a video explaining the new service:

The concept is simple - your phone becomes your boarding pass, so you scan it at the security checkpoint and also at your boarding gate. I love this technology, if only because today's boarding passes are well...terrible.

Many boarding passes printed at the airport (especially at kiosks) are now longer on nice, heavy cardstock, and (relatively) flimsy paper now seems to be the norm. I find these passes to easily crumple up in a pocket*. Carrying around an online pass printed on 8.5"x11" paper isn't exactly the most convenient option, either. I am, however, already carrying around my phone.

That isn't to say that mobile boarding passes are totally perfect, either. The biggest issue I've found thus far is that mobile boarding isn't available in a great deal of cities. Only a few non-hub/focus city destinations in the US Airways network have the technology, for example. And, of course, you to make sure your phone is charged!

Here are the US airlines that I could find with mobile boarding pass technology. Each airline's name is linked to an webpage (maintained by the airline) with more information, such as what cities have them as an option:

• Alaska
• American
• Continental
• Delta
• United
• US Airways

Oftentimes you'll be informed if mobile check-in is available at an airport where you're traveling during online check-in, so check it out!

*The one exception I've found to this rule is Virgin America's kiosk boarding passes. They're printed on cardstock, and also smaller than most boarding passes, fitting perfectly in a pants pocket.

Of course, this should shock no one. Spirit is the same airline that now charges for carry-on luggage. Ancillary revenue is kind of their thing. Fortunately, this fee is avoidable!

If you wish to check-in at the airport and have your boarding pass printed by an agent, that will cost you $5. (This applies to tickets booked on or after June 23 for travel on or after November 1.) Boarding passes at kiosks and online will still be free. But, on June 26, 2012, boarding passes at kiosks will cost you $1.

The $5 fee, however, is "waived in cities where Spirit does not have airport check-in kiosks or if a customer is not able to use the automated kiosk to print their boarding pass."

Is this new fee annoying? Yes. But Spirit's business model revolves around ancillary revenue, and this new fee is just another part of that. So, if you're planning to fly Spirit just make sure you're aware of their fee structure so you're not shocked at the airport!

Like any other business, an airport needs to generate revenues to cover its operating expenses. First, there are the landing fees charged to the airlines, which for all intents and purposes are paid for with your fare. Second, airports can impose a passenger facility charge (PFC), which is added on to a passenger's base fare and goes back to the airport. This fee is currently capped at $4.50, though some airports are hoping that this cap is increased.

Of course, the airlines don't really like that idea. Even though PFCs aren't part of the fare, passengers only really care about the total amount they're paying, and now how much of it is going to the government. We'll have to see how it plays out.

The other major sources of airport revenue? Things like retail, food, and parking. Here, passengers actually have some choice. And for that third revenue...considering this is the blog for About Airport Parking, after all...I'd be remiss if I didn't mention that this website can help. It's easy (and free!) to find the prices of parking at many major airports here, so it's at least worth comparing the prices of off-airport lots found here to what the airports offer in terms of parking, and see how much you can save!

The homepage is simple, yet elegant. Text forms that are larger than other travel websites make entering information easy. The calendar tool is easy to use, and color coding makes viewing your travel easier.

Where hipmunk really shines, however, is its display of the itineraries that it finds. It's easy to see the amount of time each itinerary will take, and layover are prominently displayed. (More information is shown when you click on an itinerary). Flights can be sorted a few different ways. Hipmunk's default sort setting is "agony," which it describes as a combination of "price, duration, and number of stops," but you can also sort by price, stops, departure time, arrival time, and duration.

Is hipmunk my new booking engine of choice? Honestly, I'm not sure yet. But it's definitely worth checking out.

So here's my question. Is this really all that big a deal? Yes, it's sad to see something that's free go away but we're only talking about a snack here, and it's not like Continental promoted its snacks like JetBlue does. (If Continental was still serving free meals in coach that would be a different story.)

What do you think?

This is an incredibly easy way to get some free miles - so you might as well give it a shot. You can get all the details here.