That looks so easy!
It’s nice, but he’s not making a whole nozzle in 15 seconds, just drilling a hole through one. 
Acorn nuts are easy to come by in a variety of sizes. Looks like a nice technique for centering the drill bit!
The problem with this is that an acorn nut isn’t quite the correct profile to get a good print out. You need to have enough clearance that heat doesn’t blast your part (that’s why you see the sharp tips on printers like the Ultimaker), and a flat which serves to push and flatten the extrudate a tiny bit. It’ll get your plastic out, it just won’t look pretty.
Nozzles are not exactly among the most expensive parts of a printer so I think I’ll buy ready made reliable ones.
I was aware of self center drilling before but I thought the drilling technique with hand holding the bit was interesting. I definately see other situations where this could come in handy for us poor lathe-less folk 
(On the specific subject of machining prototype nozzles and the outer dimensions the brave can try this;
Though I believe it’s a bit of a hit-and-miss operation since the dome can crack open if ground down too thin)
@John_Ridley - the E3D hotend makes filament changes easier then even the J-Head - you don’t always have to heat it up to remove the old filament, and it has proven considerably more reliable in my experience then the J-Head
Great TIP Thank you !
Where on earth did he get a 1/64 in (0.4mm) drill bit?
@John_Ridley you definately have a point there with changing colors. I’ve only done black PLA and ABS so I haven’t had that problem yet.
@NathanielStenzel not sure. I’ve got my 0.3 and 0.4mm bits on ebay.
http://www.ebay.com/itm/10x-0-3mm-NEW-Carbide-PCB-Dremel-Jewelry-CNC-Drill-Bits-/130401272644?ssPageName=ADME:L:OC:GB:3160
http://www.ebay.com/itm/10x-0-4mm-NEW-Carbide-PCB-Dremel-Jewelry-CNC-Drill-Bits-/140418100959?ssPageName=ADME:L:OC:GB:3160
They are so far untested but they look fine.
Ah. Newark.com may work for me. They sell one.
This might do too.