Enderpearl tossed in nether portal teleports to the coords from the overworld in the nether

When you toss an enderpearl from within an nether portal onto a block (like the side of the portal), the enderpearl goes through and notes those coordinates and then teleports you to those coordinates but in the nether which makes for stupidly fast travelling.

This is a desmonstration and better explaination
https://www.youtube.com/watch?v=DOCH8y0VdVo