Have you noticed that padding on airline seats is getting thinner? Back in the days of the Lockheed Constellation and the DC-6, seats used to be less punishing -- they were more like the cushy La-Z-Boys your dad used to lounge in.

But don't expect to find anything similar your next economy-class flight. Today, in order to save fuel and squeeze in more passengers, the padding has been minimized -- and, as we all know, the rows of seats have been placed closer together.

All of this adds up to considerable discomfort, unless you happen to have a well-padded back porch. So here are some strategies from Airfarewatchdog.com to alleviate the pain.

Making the best of economy class

Fly JetBlue: This is easy. JetBlue now offers a new program called Even More Legroom on its Airbus jets, with 38 inches of legroom in rows 2-5 of its Airbus 320 fleet and in emergency exit rows (all other rows have 34 inches or seat pitch; seat pitch is the distance between any one point on the seat and that same point in the row ahead or behind). Some airlines have 32 or even 31 inches between seats, so this is generous by airline standards these days. The extra legroom is also available in exit rows of JetBlue’s Embraer 190 jets. Since most domestic first class seats offer 38-40 inches of legroom, this is a pretty good deal. The upcharge ranges from $10-$20 depending on the length of the flight.

Pay for exit rows

Some people think it's obnoxious to charge for what was once free, but this perk is well worth it. Northwest and AirTran will sell you an exit row seat for an additional charge. Frequent flyers on Northwest get to reserve these seats when booking, for free if they're "elite" members. Mere mortals can book them within 24 hours of flight time.  Northwest also sells other "premium" seating for $5 to $35 per leg.  International seats cost $50 for trans-Pacific and Eastbound trans-Atlantic travel on Northwest-operated flights and $25 from Japan to other Asia destinations, Guam, Saipan or Hawaii. If you make a connection, you pay a separate fee for each flight. Airtran charges $20 each way (nonstop or connecting) for an exit row seat.

Premium economy

When passengers are checking in, United Airlines sometimes offers them upgrades to "Economy Plus," which has up to 5 inches more leg room, for relatively little money. If you're a frequent United customer, check out Economy Plus Access, which allows you to reserve economy plus for yourself and a guest for a full year of travel. The basic plan costs $349 per year.

If you're an elite member of United's MileagePlus program, you'll be offered complimentary, space-available Economy Plus seating.

Fly Smaller Airlines

If you're flying somewhere on its route network, AirTran offers very inexpensive confirmed upgrades to its roomier business class. Pay from $40 to $140 and you can upgrade from any full-price coach fare at the time of purchase. For about a year now, AirTran has offered a "special promotion," with first come, first served upgrades from any fare, not just full fare coach.

Spirit Airlines sells what it calls a "Big Front Seat," with two-by-two seating, at the front of its planes, for far less than other airlines charge. Don't expect any amenities other than a more comfortable seat: there's no free booze.

Midwest Airlines has all first-class seating -- every row of the plane -- on some routes, all at economy-class prices (Midwest calls this "Signature Service"). The food for purchase is great, too. Recently, the airline has added a few rows of "Signature" seats to its entire jet fleet, charging $65 per flight to those who wish to upgrade.

Upgrading to business or first for less

Use frequent flyer miles

With economy cabins so crowded and uncomfortable, and with coast to coast flights still available for $200 round-trip when there's a sale, I think the best way to use frequent flyer miles these days is to upgrade to first or business class rather than to buy economy fares. Depending on the route, the fare you paid, your frequent flyer status, and airline, mileage upgrades from economy to business or first "cost" as little as 7,500 miles each way.

It's important to note that airlines vary as to how many miles they require to upgrade a discounted economy fare. American charges 15,000 mileage points to upgrade "most" economy domestic fares, and 7,500 miles from full coach. Delta charges 5,000 miles for full-coach upgrades and 10,000 miles for upgrades from "select" discount fares. (It is very mysterious about what these fares are, advising passengers to "check with Delta.")

Seasonal business class specials

From time to time, airlines have very good deals on business and first class. Just look under the specials section of your favorite airline's Web site, or at the Airfarewatchdog.com blog. In a repeat from years past, Continental has a sale on its very comfortable BusinessFirst cabin to Europe for  travel this summer, although there are restrictions, such as lengthy advance purchase and minimum stay requirements. Fares are less than half what you'd normally pay. Other airlines are likely to follow suit. Several other airlines, both US and foreign based, also offer heavily discounted, but restricted, business class fares to Europe this summer. Also look at the newer all-business-class airlines, such as L'Avion, EOS, and Silverjet. They're rewriting the fare rules for international business class, and offer frequent specials, such as two-for-one fares. Silverjet has business class this summer from New York to London for under $2000 round-trip.

First/business class consolidators

Another strategy is to buy first- or business-class fares from consolidators. The Web site 1stair.net specializes in low cost business and first class fares at savings of 50% or more. Another good source is Planet Amex/Cook Travel. These discounted fares may have restrictions that full fare business- and first-class fares don’t have.

UP fares

On many domestic routes, most airlines offer what they call "Y UP," "H UP" and "Q UP" fares -- that's "UP" as in "upgrade." These are restricted full-fare economy fares that can be upgraded at the time of purchase to confirmed business or first class for much less than a full first-class fare. The only downside is that they're not changeable or fully refundable without paying a penalty.

You can find these fares by searching for business- or first-class fares "with restrictions," or choose the "all types" option. On Travelocity, for example, to include restricted business/first fares, you need to click on the less-than-obvious "more search options" link from the home page and then search for business class, then choose "All Types" under the fare type selector. So, for example, you could find a confirmed first class flight on Delta from New York JFK to Los Angeles for $1,200 roundtrip plus tax. Clicking on the "adult fare rules" you'll see this fare code: H7UPNBV (see the "UP"?). A fully refundable "Y" fare on this route might cost $400-$800 more.

Attain upper levels of frequent flyer programs

Frequent flyers already know this route to a comfortable seat. Many airlines will award free or low-cost space-available upgrades to their very best customers, so it really does pay to fly often and to give all your business to just one airline.

It doesn't hurt to dress and act nicely

A friend of mine was flying on Air Canada from San Francisco to Vancouver recently, and the gate agent handed him a first-class boarding pass even though he had bought an economy ticket. He asked why he was being upgraded, and she told him, "Well, you're very nicely dressed and the station manager put you in first class." Simple as that.

It doesn't happen all the time, but it does happen. Airlines tend to re-assign their best customers to first class if there are no seats left in economy, especially when flights are oversold or canceled. These are called "operational upgrades," in airline-speak. If you're an upper level frequent flyer and there's only one seat left in first class but a lot of people with the same frequent flyer status are waiting at the gate for upgrades, it seriously doesn't hurt to stand out as the nicest, friendliest, and best dressed customer. All else being equal, why wouldn't they choose you over the others?

And whatever airline you're flying, it never hurts to ask if the check in agent can offer a paid (or even a free) upgrade to a more comfortable seat. You'll sometimes see airlines tinker with upgrade options, often just before departure, and you just never know what you'll find if you ask.