Friction drilling through metal
Adam Rifkin stashed this in Tools!
Source: Reddit gifs
Its a different kind of bit. There isn't really a sharpened tool edge on it, its more of a heat resistant and abrasive cone. As for the advantages, you can drill more holes per bit and drill the holes faster but the bits are crazy expensive, so they're mainly usedin mass production kind of things.
Friction welding:
3:57 PM Dec 27 2012