By jumping onto a block midair and holding down, you are able to zip in multiple directions upon release if you do it right. We don't quite have full control over it yet, by it can have a lot of applications. Here's a clip of me zipping right into the final Dungeon.

Vaan has also applied it to water temple to save a bunch of time. There's still a lot of exploration to do, but I think we can save a lot of time with it.