Well not yet, but several U.S. airlines are taking a look at the SkyRider, a saddle-type seat that's roughly akin to sitting on a saddle. The unlucky passengers would be at a slight angle, with the seat in front no more than 23 inches away. From USA Today:
"We feel extremely confident that this concept will ... have great appeal to airlines for economic purposes," says Dominique Menoud, director general of Aviointeriors Group. The SkyRider could be its own class of seating, like business or coach, Menoud says. Passengers would likely pay lower fares. But airlines could boost their profits because the narrowly spaced seats would allow them to squeeze more fliers on board.
Aviointeriors, an Italian firm, will introduce the SkyRider at an aviation conference in Long Beach next week.