fast and the furious made this term more widely known, but never described it. I was always told its where you clutch to shift, put it in neutral, rev it to almost redline, let off and clutch then shift into new gear. Does anyone do this? Does it help?

That description is not quite correct.
Modern vehicles have synchronizers so we don't have to double clutch.

F&F is all Hollywood make believe kinda like Pinks.

Please explain how Pinks is make believe.

Pinks was originally supposed to show what the real world of Street Racing was like.
Thing is in the real world you don't get best 3 out of 5 and people don't run for titles they run for MONEY. It's one race and you don't need to out race the other guy you need to out play the other guy. Up here in Detroit during the fair weather this happens every weekend in several different locations.
The Pinks All Out Shows are much better IMO. Regardless if it's on TV it's all about entertainment. Too many Kids come out to the street races and think their going to get the same treatment as on pinks because that's all they know. Unfortunately for them that is NOT how it works.

Thank's for clarifying that. I agree with whay you have said.

i was just kinda wondering if this was actually done really. i've never done it myself...and the only time i've heard of it done is when a guy was doing donuts. i don't really understand the whole concept of it and i only know through hearsay. and pinks is ridiculous. getting car lengths on a guy? there to race AND win. not to ask for car lengths or give excuses of why you lost.

Actuallydouble clutching comes from the early days of trucking. The big rigs up until about 1960 didn't have syncronized transmissions, therefore the driver would have to double clutch to make the gears mesh.This was done by going to neutral between gears and by reducing or applying throttle to try to match the engine speed to transmission speed. Either that or it was ''FIND EM OR GRIND EM!!