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If you're on the tall side, the view from the the cheap seats may be blocked by your knees on your next airline flight.

In an effort to generate more revenue, some airlines are cutting even further into available leg room to cram more seats onto their planes, and to create extra legroom for premium seats that come at an extra cost. The Boston Globe reported Southwest Airlines has lost an inch of room between seats by adding six more seats to its planes, and that the Canadian airline WestJet will create a section of higher-fare seats by cutting inches of existing legroom from non-premium seats.

JetBlue has also cut an inch of legroom from seats in the rear rows of its Embraer E190 to provide more legroom for premium seats at the front of the plane. The airline expects to bring in $150 million on extra-legroom seats, the paper reported.

The industry standard for legroom is considered to be 31 inches, but what's standard may change. Airlines continue to cut space as passengers become conditioned to paying for every amenity. Spirit Airlines, known for having some of the cheapest flights around, has as little as 28 inches of legroom between its seats. It's the airline the traveling public loves to hate, but charging for every "extra" has proved profitable for Spirit: Its 2012 second-quarter profits were double what they were a year prior, largely due to a la carte fees.

Nearly every domestic airline now has an option for purchasing a seat with additional legroom. For example, Delta Airlines Economy Comfort promises three to four inches of extra legroom and seats that recline up to 50 percent more. United's Economy Plus offers up to five more inches of legroom. Prices vary by route and airlines, but generally run between $40 - $100 per flight segment, though the price may be lower on very short flights.

Not all economy-class seats are created equal. Legroom, seat width and pitch vary by airline and by aircraft. Sites such as seatguru.com allow passengers to search by flight number and view seat details on their flights in order to choose the most desirable option.