Outside in

In Ultimate frisbee, a throw that is thrown in the direction you are facing, but curves in the opposite direction. So a backhand thrown by a right hander would be thrown to the left(since a backhand is thrown from the left side of a right hander) and would curve right. This is useful for throwing down the sideline, around defenders and many other things. Be sure to get lots of spin on an outside in throw so that it doesn't blade into the ground. The best way to catch an outside in throw is if you can get a hand on the inside of the disc, so that if the spin causes the disc to bounce off your hand, it will bounce right into your body.

Outside in is the opposite of inside out.

"Outside In" is the name of a math film, reviewed by the math movie reviewers.

Despite the obvious lacking of well-rouded characters, the two narrators of this film explained some pretty interesting stuff. They explained how one can topologically turn a sphere inside out. What this means is that a sphere can be turned inside out by deforming it, but without cutting or gluing it. In much the same way, a coffee cup can be seen to be topolocially equivalent to a donut because both are one-holed surfaces, known to mathematicians as tori (singular, torus). It's rather odd to think that a sphere can be turned inside-out in this way, because a plain old two dimensional circle cannot.

So how did they perform this amazing act of contortion? Well, first they showed that a circle cannot be turned inside out. This had to do with orientation and turning numbers, which were demonstrated using a monorail car making turns around one full trip. Understanding the sphere involved viewing it as a rounded cylinder with polar caps and rather funky looking edges. If you want to know what it looks like, see the film.