You can choose to fly first class, economy, or perched on a bicycle seat.
Airbus filed a patent application for airline "bicycle seats," which are exactly what the name says they are—bike seats mounted on vertical bars that passengers would sit on for the duration of their flight. The tray table-, headrest-, and legroom-lacking design skimps on comfort but maximizes space efficiency.
According to the LA Times, the patent application, submitted in Europe, explains that the intent of the bicycle seat is to reduce the bulk of airplane seating and allow more passengers to board flights.
"'Low-cost' airlines seek to increase the number of passengers transported on each flight, and more particularly on short-haul links, in order to maximize the return on the use of the aircraft," the patent description states. "The number of seats in a cabin must be increased, to the detriment of the comfort of the passengers."
If Airbus is ever able to utilize its bicycle seats, we hope it will spend any extra profits on special classes to teach pilots to avoid all turbulence.